Honeywell CH Programmer CM927 - Can it be repaired?

Bendy_House

Most boilers have a frost setting built in. The issue here is about having better control so it saves you money.

You could leave all your TRVs on 'frost' setting, but what about the boiler? Will you leave it timed to be 'always on'? If so, it'll keep firing up and trying to shift the heated water, which it'll fail to do so it shuts down again, and back on when that water cools. That's called 'cycling'.

With my Hive, I open the App, select 'manual', and - ooh - 6oC. Jobbie jobbed. And then I can check what the ACTUAL house temp is and has been, and how often - if at all - the boiler has come on.

If I was away during a sudden very cold snap, I could tweak up the temp from my Caribbean resort to, say, 10oC if I felt it was necessary.

I think it's worth checking what can of control your new boiler is capable of, and investigating this further. But if you are just considering swapping your 

Leodogger

As far as I am aware our boiler (according to the man who fitted it) has a frost setting so will only switch on if it the temp gets below 5c I think.   Why would the boiler switch on at all if it is set on the frost setting ?   Surely it only cycles when a person calls on it for hot water or heating, neither of which we will be using whilst away ?

BUFF

If it is an 18 month old Worcester then it terms of absolute efficiency I would recommend a Worcester control system (Worcester have their own controls communication protocol, EMS). It will be able to extract the last few % of efficiency from the system that others won't. Did the installer not advise you to upgrade controls at the same time?
https://www.worcester-bosch.co.uk/products/boiler-controls/directory/greenstar-comfort-ii-rf-1 or EasyControl (their "smart" solution) https://www.worcester-bosch.co.uk/products/boiler-controls/bosch-easycontrol

If they don't have a solution that suits you  for whatever reason I have very much come around to Drayton Wiser, my only niggle is that it is not the most attractive of units to my eyes.

The frost setting on your boiler is only to protect the boiler from freezing internally & damage to the heat exchanger etc.. It probably kicks in ~5-7C.
If you have "dumb" TRVs they can't call for heat to the boiler themselves.
You also want to check that your house insurance doesn't have a clause requiring you to heat it to a minimum level (12C seems common) if you are going to be a way for a long period (there is probably also a clause for period unoccupied).

Bendy_House said:

BUFF said:

Leodogger said:

BUFF said:

Leodogger said:

BUFF said:

Leodogger said:

BUFF said:

there are direct replacements for CM927s (hopefully without the screen issues) if you wanted to do a straight swap

Like what?

Honeywell say the T4 or T4R.

Also, https://theintergasshop.co.uk/home/99-cms927-7-day-wireless-programmable-room-thermostat-cms927b1049.html etc. (if you search you may find this cheaper elsewhere)

Although my sister told me not to bother and just use the TRV's on the radiators and turn the heating off and on with those and save myself £80 like she does!    These programmers only last about 6-7 yrs by the looks of it, another throw away item in today's world where eco people and the government batter you to go green and not throw things away with no one supplying the repair shops to provide the solution to repair these thousands of appliances people end up dumping because they can't be repaired.   

Having previously run a system with TRVs only + programmer myself I can tell you confidently from personal experience that the room 'stat/programmer used properly will save you a significant amount of gas consumption/money.
My wireless room 'stat is a 14 years old Siemens, the programmer is a similarly aged Worcester (really a badged Drayton) & both are still going strong. 

Well as I said, my programmer is only about 6 or 7 yrs old which I don't think is old for something that will cost £100 to replace!   My washer only cost just over £200 and I consider that a far more useful appliance that will last at least as long if not longer.  My last washer lasted 13 yrs !!

I agree. However, looking at internet feedback it would appear that this particular series has an issue with the LCD panel. I am reasonably sure that Honeywell didn't design it to be that way but that was the outcome (supplier issue?).
Also, since your Honeywell was designed there have been improvements in heating system controls that mean that they will usually more than pay for themselves by reduced running costs (especially with gas at 10pkWh) over their life.

p.s. I know that B_H is a big fan of Hive but it is one of the poorer "smart" thermostats in terms of energy efficiency, it is a Class 1 thermostat which is the lowest ranking.

Absolutely. The Hive suits me and my 16- year old Glowworm just fine! All it does is turn the boiler on and off, just like a room stat, but it takes all the 'operator error' out of it.

Better systems will not only tell the boiler to go on and off, but also by how much. It'll control a boiler's output more like adjusting a gas hob - a range of 'burn'.

And then there's weather compensation, so it again adjusts the boiler according to the outside conditions.

But, your boiler has to have these features as well.

If your boiler is 'oldish' like mine, it's still probably worth future-proofing your controls in anticipation of a boiler replacement at some point - the additional amount for these 'super' controls is probably not much.

My 14 year old Siemens room  'stat is a Class 4 (it incorporates TPI https://youlearn.honeywellhome.com/uploads/documents/FAQ_-_TPI_functionality.pdf).
Wiser on a combi afaik is a Class VII (that may require Opentherm though?).
https://phpionline.co.uk/feature-articles/erp-control-classes/

Leodogger

BUFF said:

If it is an 18 month old Worcester then it terms of absolute efficiency I would recommend a Worcester control system (Worcester have their own controls communication protocol, EMS). It will be able to extract the last few % of efficiency from the system that others won't. Did the installer not advise you to upgrade controls at the same time?
https://www.worcester-bosch.co.uk/products/boiler-controls/directory/greenstar-comfort-ii-rf-1 or EasyControl (their "smart" solution) https://www.worcester-bosch.co.uk/products/boiler-controls/bosch-easycontrol

If they don't have a solution that suits you  for whatever reason I have very much come around to Drayton Wiser, my only niggle is that it is not the most attractive of units to my eyes.

The frost setting on your boiler is only to protect the boiler from freezing internally. It probably kicks in ~5-7C.


Bendy_House said:

BUFF said:

Leodogger said:

BUFF said:

Leodogger said:

BUFF said:

Leodogger said:

BUFF said:

there are direct replacements for CM927s (hopefully without the screen issues) if you wanted to do a straight swap

Like what?

Honeywell say the T4 or T4R.

Also, https://theintergasshop.co.uk/home/99-cms927-7-day-wireless-programmable-room-thermostat-cms927b1049.html etc. (if you search you may find this cheaper elsewhere)

Although my sister told me not to bother and just use the TRV's on the radiators and turn the heating off and on with those and save myself £80 like she does!    These programmers only last about 6-7 yrs by the looks of it, another throw away item in today's world where eco people and the government batter you to go green and not throw things away with no one supplying the repair shops to provide the solution to repair these thousands of appliances people end up dumping because they can't be repaired.   

Having previously run a system with TRVs only + programmer myself I can tell you confidently from personal experience that the room 'stat/programmer used properly will save you a significant amount of gas consumption/money.
My wireless room 'stat is a 14 years old Siemens, the programmer is a similarly aged Worcester (really a badged Drayton) & both are still going strong. 

Well as I said, my programmer is only about 6 or 7 yrs old which I don't think is old for something that will cost £100 to replace!   My washer only cost just over £200 and I consider that a far more useful appliance that will last at least as long if not longer.  My last washer lasted 13 yrs !!

I agree. However, looking at internet feedback it would appear that this particular series has an issue with the LCD panel. I am reasonably sure that Honeywell didn't design it to be that way but that was the outcome (supplier issue?).
Also, since your Honeywell was designed there have been improvements in heating system controls that mean that they will usually more than pay for themselves by reduced running costs (especially with gas at 10pkWh) over their life.

p.s. I know that B_H is a big fan of Hive but it is one of the poorer "smart" thermostats in terms of energy efficiency, it is a Class 1 thermostat which is the lowest ranking.

Absolutely. The Hive suits me and my 16- year old Glowworm just fine! All it does is turn the boiler on and off, just like a room stat, but it takes all the 'operator error' out of it.

Better systems will not only tell the boiler to go on and off, but also by how much. It'll control a boiler's output more like adjusting a gas hob - a range of 'burn'.

And then there's weather compensation, so it again adjusts the boiler according to the outside conditions.

But, your boiler has to have these features as well.

If your boiler is 'oldish' like mine, it's still probably worth future-proofing your controls in anticipation of a boiler replacement at some point - the additional amount for these 'super' controls is probably not much.

My 14 year old Siemens room  'stat is a Class 4 (it incorporates TPI https://youlearn.honeywellhome.com/uploads/documents/FAQ_-_TPI_functionality.pdf).
Wiser on a combi afaik is a Class VII (that may require Opentherm though?).
https://phpionline.co.uk/feature-articles/erp-control-classes/

Don't know what you mean by "upgrade controls".    We had the programmer from our previous boiler but the CH engineer said it was quite oK to use it with this new Worcester boiler.     

BUFF

Leodogger said:

BUFF said:

If it is an 18 month old Worcester then it terms of absolute efficiency I would recommend a Worcester control system (Worcester have their own controls communication protocol, EMS). It will be able to extract the last few % of efficiency from the system that others won't. Did the installer not advise you to upgrade controls at the same time?
https://www.worcester-bosch.co.uk/products/boiler-controls/directory/greenstar-comfort-ii-rf-1 or EasyControl (their "smart" solution) https://www.worcester-bosch.co.uk/products/boiler-controls/bosch-easycontrol

If they don't have a solution that suits you  for whatever reason I have very much come around to Drayton Wiser, my only niggle is that it is not the most attractive of units to my eyes.

The frost setting on your boiler is only to protect the boiler from freezing internally. It probably kicks in ~5-7C.


Bendy_House said:

BUFF said:

Leodogger said:

BUFF said:

Leodogger said:

BUFF said:

Leodogger said:

BUFF said:

there are direct replacements for CM927s (hopefully without the screen issues) if you wanted to do a straight swap

Like what?

Honeywell say the T4 or T4R.

Also, https://theintergasshop.co.uk/home/99-cms927-7-day-wireless-programmable-room-thermostat-cms927b1049.html etc. (if you search you may find this cheaper elsewhere)

Although my sister told me not to bother and just use the TRV's on the radiators and turn the heating off and on with those and save myself £80 like she does!    These programmers only last about 6-7 yrs by the looks of it, another throw away item in today's world where eco people and the government batter you to go green and not throw things away with no one supplying the repair shops to provide the solution to repair these thousands of appliances people end up dumping because they can't be repaired.   

Having previously run a system with TRVs only + programmer myself I can tell you confidently from personal experience that the room 'stat/programmer used properly will save you a significant amount of gas consumption/money.
My wireless room 'stat is a 14 years old Siemens, the programmer is a similarly aged Worcester (really a badged Drayton) & both are still going strong. 

Well as I said, my programmer is only about 6 or 7 yrs old which I don't think is old for something that will cost £100 to replace!   My washer only cost just over £200 and I consider that a far more useful appliance that will last at least as long if not longer.  My last washer lasted 13 yrs !!

I agree. However, looking at internet feedback it would appear that this particular series has an issue with the LCD panel. I am reasonably sure that Honeywell didn't design it to be that way but that was the outcome (supplier issue?).
Also, since your Honeywell was designed there have been improvements in heating system controls that mean that they will usually more than pay for themselves by reduced running costs (especially with gas at 10pkWh) over their life.

p.s. I know that B_H is a big fan of Hive but it is one of the poorer "smart" thermostats in terms of energy efficiency, it is a Class 1 thermostat which is the lowest ranking.

Absolutely. The Hive suits me and my 16- year old Glowworm just fine! All it does is turn the boiler on and off, just like a room stat, but it takes all the 'operator error' out of it.

Better systems will not only tell the boiler to go on and off, but also by how much. It'll control a boiler's output more like adjusting a gas hob - a range of 'burn'.

And then there's weather compensation, so it again adjusts the boiler according to the outside conditions.

But, your boiler has to have these features as well.

If your boiler is 'oldish' like mine, it's still probably worth future-proofing your controls in anticipation of a boiler replacement at some point - the additional amount for these 'super' controls is probably not much.

My 14 year old Siemens room  'stat is a Class 4 (it incorporates TPI https://youlearn.honeywellhome.com/uploads/documents/FAQ_-_TPI_functionality.pdf).
Wiser on a combi afaik is a Class VII (that may require Opentherm though?).
https://phpionline.co.uk/feature-articles/erp-control-classes/

Don't know what you mean by "upgrade controls".    We had the programmer from our previous boiler but the CH engineer said it was quite oK to use it with this new Worcester boiler.     

Upgrade as in improve. The programmer part is fine (when the screen works) & after some hunting it is apparently a Class 4 thermostat.
The Worcester Comfort II Rf is a Class 5.
The Worcester EasyControl is a Class 6  or if fitted along with at least 3 Bosch electronic TRVs a Class 8.

If the Worcester controls had been fitted at the same time as your boiler then they could/would have been warrantied for as long as the boiler.

Leodogger

Just spoken to my central heating engineer and he said we really need to get a new thermostat controller and has suggested the ESI which he said never lets people down.  He said they are £80 to supply + fitting cost.    Is that a fair price?   Or do I need an engineer at all to supply this to me and what fitting is involved ?

BUFF

Which ESI, this one https://www.esicontrols.co.uk/product/4-series-wireless-programmable-room-thermostat/ ?
You can buy those for £50  (Class 5 if used with an Opentherm boiler which yours is not).
https://www.google.com/shopping/product/3082996712060455729/offers?q=ESRTP5WiFi

I suspect that it's a fairly easy swap.

Leodogger

BUFF said:

Which ESI, this one https://www.esicontrols.co.uk/product/4-series-wireless-programmable-room-thermostat/ ?
You can buy those for £50  (Class 5 if used with an Opentherm boiler which yours is not).
https://www.google.com/shopping/product/3082996712060455729/offers?q=ESRTP5WiFi

I suspect that it's a fairly easy swap.

I think he said that he has to fit the Receiver to the boiler too, perhaps that is what adds to the cost of the whole thing.

bob_a_builder

Leodogger said:

Bendy_House said:

BUFF said:

Leodogger said:

BUFF said:

Leodogger said:

BUFF said:

Leodogger said:

BUFF said:

there are direct replacements for CM927s (hopefully without the screen issues) if you wanted to do a straight swap

Like what?

Honeywell say the T4 or T4R.

Also, https://theintergasshop.co.uk/home/99-cms927-7-day-wireless-programmable-room-thermostat-cms927b1049.html etc. (if you search you may find this cheaper elsewhere)

Although my sister told me not to bother and just use the TRV's on the radiators and turn the heating off and on with those and save myself £80 like she does!    These programmers only last about 6-7 yrs by the looks of it, another throw away item in today's world where eco people and the government batter you to go green and not throw things away with no one supplying the repair shops to provide the solution to repair these thousands of appliances people end up dumping because they can't be repaired.   

Having previously run a system with TRVs only + programmer myself I can tell you confidently from personal experience that the room 'stat/programmer used properly will save you a significant amount of gas consumption/money.
My wireless room 'stat is a 14 years old Siemens, the programmer is a similarly aged Worcester (really a badged Drayton) & both are still going strong. 

Well as I said, my programmer is only about 6 or 7 yrs old which I don't think is old for something that will cost £100 to replace!   My washer only cost just over £200 and I consider that a far more useful appliance that will last at least as long if not longer.  My last washer lasted 13 yrs !!

I agree. However, looking at internet feedback it would appear that this particular series has an issue with the LCD panel. I am reasonably sure that Honeywell didn't design it to be that way but that was the outcome (supplier issue?).
Also, since your Honeywell was designed there have been improvements in heating system controls that mean that they will usually more than pay for themselves by reduced running costs (especially with gas at 10pkWh) over their life.

p.s. I know that B_H is a big fan of Hive but it is one of the poorer "smart" thermostats in terms of energy efficiency, it is a Class 1 thermostat which is the lowest ranking.

Absolutely. The Hive suits me and my 16- year old Glowworm just fine! All it does is turn the boiler on and off, just like a room stat, but it takes all the 'operator error' out of it.

Better systems will not only tell the boiler to go on and off, but also by how much. It'll control a boiler's output more like adjusting a gas hob - a range of 'burn'.

And then there's weather compensation, so it again adjusts the boiler according to the outside conditions.

But, your boiler has to have these features as well.

If your boiler is 'oldish' like mine, it's still probably worth future-proofing your controls in anticipation of a boiler replacement at some point - the additional amount for these 'super' controls is probably not much.

Actually my boiler is only 18 months old and has a frost setting as do all the radiators, so I wouldn't have thought if I leave them switched to that, my boiler would be firing all the time, especially as our bungalow is quite well insulted and rarely gets down below about 12c with no heating on.   But as we are going to be away for a few months, I am still wondering if I need a programmer ?

You say you are going away for a couple of months  - most house insurances wont cover you past 30 days ?  

If you take out un-occupied insurance for that period - they will have clauses regarding your heating as attached 

How would you maintain 12 deg without a programmable stat

Leodogger

bob_a_builder said:

Leodogger said:

Bendy_House said:

BUFF said:

Leodogger said:

BUFF said:

Leodogger said:

BUFF said:

Leodogger said:

BUFF said:

there are direct replacements for CM927s (hopefully without the screen issues) if you wanted to do a straight swap

Like what?

Honeywell say the T4 or T4R.

Also, https://theintergasshop.co.uk/home/99-cms927-7-day-wireless-programmable-room-thermostat-cms927b1049.html etc. (if you search you may find this cheaper elsewhere)

Although my sister told me not to bother and just use the TRV's on the radiators and turn the heating off and on with those and save myself £80 like she does!    These programmers only last about 6-7 yrs by the looks of it, another throw away item in today's world where eco people and the government batter you to go green and not throw things away with no one supplying the repair shops to provide the solution to repair these thousands of appliances people end up dumping because they can't be repaired.   

Having previously run a system with TRVs only + programmer myself I can tell you confidently from personal experience that the room 'stat/programmer used properly will save you a significant amount of gas consumption/money.
My wireless room 'stat is a 14 years old Siemens, the programmer is a similarly aged Worcester (really a badged Drayton) & both are still going strong. 

Well as I said, my programmer is only about 6 or 7 yrs old which I don't think is old for something that will cost £100 to replace!   My washer only cost just over £200 and I consider that a far more useful appliance that will last at least as long if not longer.  My last washer lasted 13 yrs !!

I agree. However, looking at internet feedback it would appear that this particular series has an issue with the LCD panel. I am reasonably sure that Honeywell didn't design it to be that way but that was the outcome (supplier issue?).
Also, since your Honeywell was designed there have been improvements in heating system controls that mean that they will usually more than pay for themselves by reduced running costs (especially with gas at 10pkWh) over their life.

p.s. I know that B_H is a big fan of Hive but it is one of the poorer "smart" thermostats in terms of energy efficiency, it is a Class 1 thermostat which is the lowest ranking.

Absolutely. The Hive suits me and my 16- year old Glowworm just fine! All it does is turn the boiler on and off, just like a room stat, but it takes all the 'operator error' out of it.

Better systems will not only tell the boiler to go on and off, but also by how much. It'll control a boiler's output more like adjusting a gas hob - a range of 'burn'.

And then there's weather compensation, so it again adjusts the boiler according to the outside conditions.

But, your boiler has to have these features as well.

If your boiler is 'oldish' like mine, it's still probably worth future-proofing your controls in anticipation of a boiler replacement at some point - the additional amount for these 'super' controls is probably not much.

Actually my boiler is only 18 months old and has a frost setting as do all the radiators, so I wouldn't have thought if I leave them switched to that, my boiler would be firing all the time, especially as our bungalow is quite well insulted and rarely gets down below about 12c with no heating on.   But as we are going to be away for a few months, I am still wondering if I need a programmer ?

You say you are going away for a couple of months  - most house insurances wont cover you past 30 days ?  

If you take out un-occupied insurance for that period - they will have clauses regarding your heating as attached 

How would you maintain 12 deg without a programmable stat

Our insurance company has agreed to cover us for 90 days with an endorsement to the policy (they normally cover for 60 days absence!).   However, I have now spoken with our CH engineer and he has agreed we will need to replace the programmer otherwise the boiler may malfunction whilst we are away and we need to set it he said to about 9c is sufficient.