Radiator TRV`s, worth it?

FUNKYDADDIO

Hi Guys,

I recently saw the Netatmo Thermostat advertised in NI half price,

https://powerni.co.uk/products-services/energy-extras/netatmo/

seems a decent deal but I already have a honeywell wireless controller for my combi gas boiler so dont think it would bring any benefit to me. It did get me thinking about TRV`s and I was wondering if anyone could recommend some? The honeywell home kit seems great but expensive when you cpmapre to what this comany Conrad have to offer and seems a similar product,

http://www.conrad-electronic.co.uk/ce/en/overview/0812040/Programmable-Thermostatic-Radiator-Valves

Many thanks in advance

CashStrapped

You will see little benifit with a"smart" wireless thermostat over what you have. The only minor benifit is that you can change it via your smartphone, and that it can turn on the heating just before you get home.

If you work irregular hours, on your own, then you will see the most benifit.

If you work regular hours and have a house where people come and go all the time, very little if any.

The honeywell evo home is a different kettle of fish. It is a more comprehensive system and is truly more of a "smart" system. This is because the individual TRVs can be programmed like zones, and you can vary the required cut-off temperature for each radiator, throughout the day.

Remember TRVs only turn off the radiator when the room has reached the set temperature, nothing more.

The downside to the evohome setup is the cost. It will be 700+ on an average semi. If you already have modern controls, again the savings may be minimal. So you are spending money to save money. It may take years to recoup the cost, if not a decade.

If budget is tight, get some good quality honeywell manual TRVs. Set them up correctly and you should not need to change them much.

People often fall into the trap of not thinking they work and turning them up full when they want a hot radiator and turning them off when they don't.

If you want the latest thing, and money is no object, it is the Honeywell evohome.

If not, and your priority is saving money, then manual TRVs are the way to go.

badmemory

I've had manual TVRs for several years now. Until I had a new big radiator put in a room which was naturally cool I never managed to catch any of the TVRs working. That one does occasionally turn the rad off.

System

CashStrapped wrote: »

The honeywell evo home is a different kettle of fish. It is a more comprehensive system and is truly more of a "smart" system. This is because the individual TRVs can be programmed like zones, and you can vary the required cut-off temperature for each radiator, throughout the day.

The downside to the evohome setup is the cost. It will be 700+ on an average semi. If you already have modern controls, again the savings may be minimal. So you are spending money to save money. It may take years to recoup the cost, if not a decade.


.

Three Winters on, my Honeywell Evohome system has reduced my annual gas consumption - pre Evohome - by c.18%. Evohome replaced a hall thermostat and conventional TRVs on all the radiators. From a simple MSE perspective, it makes little financial sense; however, the main advantage is that we have heat, at a temperature that we want, in the rooms that we use when we need it. The other not often mentioned benefit of TPI controls is that with the use of Opentherm*, Evohome will modulate your boiler demand in a much more controlled way than the weather compensation controls offered by most UK boiler manufacturers which. in turn, extends boiler life.

NB: NEST 3 now offers Opentherm control. To make this work, the boiler has to have the capability to accept this type of control input. Sadly, WB and Valliant UK do not yet support Opentherm.

Cardew

CashStrapped wrote: »

If not, and your priority is saving money, then manual TRVs are the way to go.

Agreed!

It really surprises me the money people will spend to 'Automate'(horrible word) their heating.

How difficult is it to manually set the TRVs to the required temperature in each room?

Gizmo247

Cardew wrote: »

How difficult is it to manually set the TRVs to the required temperature in each room?

Errr ...

What every night before bed, I would have to turn off the radiators in the hall, kitchen, living room and dining room and reduce the temperature in the bathroom and set a lower temperature in the bedrooms.

Then, in the morning, get up earlier than everyone else in the house, turn the radiators back on in the hall, kitchen, living room and dining room, turn up the bathroom and sneak into everyone's bedroom and turn up their radiator.

Then, at around 8am, turn off the radiators in the hall, kitchen, living room, dining room, bathroom and bedrooms again and set my bedroom temperature for working at my desk all day.

Then before, everyone gets home, turn all the radiator back on.

Sounds like a lot of effort to me. Perhaps, easier to let all that happen automatically, don't you think.

roddydogs

TRVs only work properly when the boiler is "ON", a lot of the time it isnt if the therm says the "Main room" is off, they dont work. They are of course "Better than nothing"

reeac

I assume that by "manually set TRVs in each room" Cardew means setting up the system once and then leaving it to the programmer and room stat to look after things. That's my view on TRVs .... use them to fine tune the system to compensate for any discrepancies between radiator output and heat required in each location.

ASavvyBuyer

Gizmo247 wrote: »

Errr ...

What every night before bed, I would have to turn off the radiators in the hall, kitchen, living room and dining room and reduce the temperature in the bathroom and set a lower temperature in the bedrooms.

Then, in the morning, get up earlier than everyone else in the house, turn the radiators back on in the hall, kitchen, living room and dining room, turn up the bathroom and sneak into everyone's bedroom and turn up their radiator.

Then, at around 8am, turn off the radiators in the hall, kitchen, living room, dining room, bathroom and bedrooms again and set my bedroom temperature for working at my desk all day.

Then before, everyone gets home, turn all the radiator back on.

Sounds like a lot of effort to me. Perhaps, easier to let all that happen automatically, don't you think.

Rather than doing all that, wouldn't it be easier just to set the TRV's to the required temperature for each room and then just let the programmer turn on the heating when needed and off again when it's not?.

lstar337

ASavvyBuyer wrote: »

Gizmo247 wrote: »

Errr ...

What every night before bed, I would have to turn off the radiators in the hall, kitchen, living room and dining room and reduce the temperature in the bathroom and set a lower temperature in the bedrooms.

Then, in the morning, get up earlier than everyone else in the house, turn the radiators back on in the hall, kitchen, living room and dining room, turn up the bathroom and sneak into everyone's bedroom and turn up their radiator.

Then, at around 8am, turn off the radiators in the hall, kitchen, living room, dining room, bathroom and bedrooms again and set my bedroom temperature for working at my desk all day.

Then before, everyone gets home, turn all the radiator back on.

Sounds like a lot of effort to me. Perhaps, easier to let all that happen automatically, don't you think.

Rather than doing all that, wouldn't it be easier just to set the TRV's to the required temperature for each room and then just let the programmer turn on the heating when needed and off again when it's not?.

Exactly! :wall:

System

This is probably not the best place to discuss the 'benefits' of smart controls but here goes. Forget about TRVs for the moment.

The basic hall thermostat fitted in most homes is nothing more than a bi-metallic switch with an ON/OFF function. TPI - enabled thermostats such as Nest, Danfoss and Honeywell (including the Evotouch controller) calculate boiler firing times based on the difference in temperature between the actual temperature and the target temperature. TPI-enabled thermostats will reduce boiler firing times and save money; however, like the simple ON/OFF thermostat, boiler modulation is left to the boiler to manage.

Opentherm devices such as Nest 3 and Evohome also control the gas valve to reduce boiler maximum output temperature based on TPI calculated demand. This results in a condensing boiler which spends a lot more time in the condensing mode. It also results in more accurate room temperature control as the radiators will often be warm rather than the classic hot then cold then hot routine.

The Opentherm protocol was developed at Glasgow University in 1996 and is in widespread use in The Netherlands and Germany but, as yet, not widely supported in the U.K.

Zoning adds to the above savings. Each electronic TRV has TPI and it is capable of optimised start and stop. For example, last week when the outside temperature was cold, my kitchen radiators came on about an hour before a target temperature of 20C was required. This morning, with a much higher outside temperature, the optimised start was about 35 minutes. The reverse happens when a reduced zone temperature is required. All these optimisations add to the savings.

TPI and Opentherm have also been shown to reduce boiler wear. Just one year of extra boiler life would go a long way towards covering the cost of smart controls.

All that said, finding a knowledgeable installer isn't easy in the UK.