Seeking advice on disappointing heat pump experience

QrizB

The only person in this thread who has access to your system is you. None of us can look at your consumer unit or heat pump controller for you, none of us can adjust your settings.

You can give us information, and we can help you with ideas of what to investigate. Or not. It's your choice.

LightFlare

(Removed by Forum Team)

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I was of the belief that heat pumps are more suited to newer houses,ideally with underfloor heating and excellent insulation.

A 25 year old house with semi decent insulation probably was never the ideal candidate for that system

matt_drummer

LightFlare said:

Netexporter said:

Your fundamental mistake was not doing any research before embarking on this project.

I was of the belief that heat pumps are more suited to newer houses,ideally with underfloor heating and excellent insulation.

A 25 year old house with semi decent insulation probably was never the ideal candidate for that system

My 45 year old house.

Emoncms - app view

It's doing ok

56p so far today for heating and hot water, 23c downstairs, 21c upstairs

LightFlare

matt_drummer said:

LightFlare said:

Netexporter said:

Your fundamental mistake was not doing any research before embarking on this project.

I was of the belief that heat pumps are more suited to newer houses,ideally with underfloor heating and excellent insulation.

A 25 year old house with semi decent insulation probably was never the ideal candidate for that system

My 45 year old house.

Emoncms - app view

It's doing ok

No idea what I’m looking at tbh.

But good to know I am mistaken in my beliefs.

Def need to do some proper research when I’m In the position to have to make a choice/decision

matt_drummer

LightFlare said:

matt_drummer said:

LightFlare said:

Netexporter said:

Your fundamental mistake was not doing any research before embarking on this project.

I was of the belief that heat pumps are more suited to newer houses,ideally with underfloor heating and excellent insulation.

A 25 year old house with semi decent insulation probably was never the ideal candidate for that system

My 45 year old house.

Emoncms - app view

It's doing ok

No idea what I’m looking at tbh.

But good to know I am mistaken in my beliefs.

Def need to do some proper research when I’m In the position to have to make a choice/decision

Basically it is 500% efficient since installation.

I pay 7p for electricity and allowing for battery charging and discharging losses 9p at worst.

That means I pay at most 1.8p per kWh to heat my house and hot water.

The house is more than 25 years old but it still works!

Tell me where else you can heat your house these days for less than 2p per kWh?

Perhaps it is best not to make claims about the suitability of heat pumps unless you know what you are talking about?

Netexporter

LightFlare said:

Netexporter said:

Your fundamental mistake was not doing any research before embarking on this project.

I was of the belief that heat pumps are more suited to newer houses,ideally with underfloor heating and excellent insulation.

A 25 year old house with semi decent insulation probably was never the ideal candidate for that system

My late 80s (so previous building standard to OP) detached bungalow is perfectly toasty with a 5kW heat pump. I turn the temperature down to 16 degrees at night and up to 20 degrees in the day/evening.

Houses lose heat at the same rate whatever means you choose to heat them. 

matelodave

LightFlare said:

Netexporter said:

Your fundamental mistake was not doing any research before embarking on this project.

I was of the belief that heat pumps are more suited to newer houses,ideally with underfloor heating and excellent insulation.

A 25 year old house with semi decent insulation probably was never the ideal candidate for that system

a heat pump produces hot water to heat the place, even 100year old buildings can be heated with one although like any heating system extra insulation will always make it more efficient and cheaper to run.

A properly specified, installed and commissioned system should be more than adequate to heat a 25 year old house whether its got u/f heating or radiators. The major thing though is to understand how to get the best out of it operate it correctly and not try using it as a conventional boiler.

Most systems will probably be installed with default parameters and are probably tweaked a bit during commissioning but in the end its down to the user to get the settings right for their particular circumstance and lifestyle.

Bunging in a load of high tech stuff like batteries, solar and a heatpump becomes a bit of a waste if you dont use it properly. ts a bit like going from a bicycle to a car, there's a lot to learn and understand before you can drive and if you aren't willing to put the effort in then you'll never get the best out of it.

Non of us can give any suggestions on how to configure someone else's system without at least some knowledge of what it is and how its configured especially with some of the fairly aggressive responses.

Like @matt_drummer I'm out

michaels

Alex_ST said:

Seems to be a lot of confusion/disbelief about this experience. I accept that it is UNEXPECTED—hence this thread. 

From my research this certainly *should* have been a more affordable solution. From my experience, it *is not*. 

The disbelief is frankly, absurd. 

There are all sorts of things that might have gone wrong here. The design, the installation, the components, the monitoring system, the operation and probably many things I haven’t considered as a novice. 

I understood my simple old system inside out and had it running efficiently (economically on a par with a gas boiler, YES REALLY!) 

I don’t have any experience with this new system and don’t have any interest in researching it exhaustively and micromanaging every kWh—no disrespect if that’s your hobby, but it just sounds like work to me. I just want to check the most likely things to have gone wrong in this installation before I get someone in to investigate. 

So electric resistance heating should be 100% efficient compared to gas at 90-95% so if your electric price per unit was no more than 5% more than the cost of a unit of gas then electric heating could be economically advantageous.  I guess this could be achieved if you were able to use all your electricity during an E7 off peak window and then store enough energy to keep your house warm for the remaining hours of the day. 

There is also a potential further saving from having a colder temp overnight as then the overnight heat loss would also be lower - mot heat pump controls can support this in some manner.

Is tis the situation you were in with your direct electric boiler?

Exiled_Tyke

Is one of the issues here that previously the heating electricity was consumed on E7 overnight. Now the heating is way more efficient but the bulk of it is by day so at higher rates?   It seems the key to the problem is to ensure that the greater proportion of heat is used during the E7 times (unless there is a way to get a Smart meter with better overnight tariffs).  So (at the risk of covering what's already been tried). 

1. Ensure all hot water is heated overnight on E7 (mine was set up originally to do a main heat up by night on cheap rate but then reheat during the day - I reset this and set the tank temperature to the minimum needed to last through the day) 
2. For the legionella's cycle heat the water first on the ASHP  to the hottest it will go then run the legionella's cycle on the already hot water.  Run both of these on the E7 rate. (I needed to use the installer's code to change this on my system) 
3. At this time of year top the battery up from the mains (known as 'Force Time Use' on my battery set up). 
4. I have my ASHP shut off an hour before bed time and then turn on again to warm up while still in the cheap rate period. I then have it off for the morning and fire up again while there's still some sun on the panels (which isn't really worthwhile at this time of year but hopefully will be useful in the 'shoulder' months. 
5. Are there any appliances which can be switched to overnight E7 use (washing machine, dishwasher?).  Don't expect the solar panels to produce anything useful at this time of year especially with where you are in Scotland, They will do fantastically from mid-spring onwards - when you can then switch appliance use to be by day.  

Year's ago I had an E7 tariff in a house with no central heating but benefited from the hot water and other stuff going on overnight.   But I really would do everything possible to get a smart meter.  

Did anyone answer the cycling question?  If not: gas boilers tend to run with relatively hot water in the radiators and cycle on and off as needed.  ASHPs run more efficiently by being permanently on and not cycling.  Lower radiator temps improve SCOP considerably.  Which is why systems should be monitoring outside temperature and then setting the radiator flow rate to the minimum possible to maintain warmth. hence the slow warm up rate of ASHP systems.   

There really shouldn't be anything causing electricity use to double in the way you mention.  I worry that something has been set up wrongly e.g. charging the battery from the mains by day etc.