Any Central heating gurus in the house.....

LASTOLITE

LASTOLITE

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My house has a combi boiler and thermostatic valves on the rads the boiler has a timer on the boiler itself and comes on twice in the AM and the PM it all works fine but is it missing a room thermostat? I have Just regulated the individual room temps in the winter using the TRV's but a mate said a room stat in the lounge may be a good idea? do I need one will it save me money in the long term?
Im all for saving on energy bills but at what expense. do I need a spark to fit it and where and how does it connect to the boiler? I understand many are radio control now so routing cable is not required, but the boiler is in the basement - only a wood floor between lounge and basement though so Radio should get though if thats the case...

Any help on this is appreciated

TIA
 
My old system was just TRV's
I had a new system installed a couple or 3 years ago,
plus a thermostat in the dinging room.
It certainly appears to be "cost effective"
that way.
I guess though the new boiler had something to do with it also.

Can't help with the cost though as mine was "all in"
TBH I wish I had gone for the remote one, due to the flexibility,
but I wasn't aware or their existence at the the time
 
Depending on what boiler you have will depend on what RF stat you can fit, some are 240v (to the receiver) and some are 24v. It goes without saying that if you put 240 through a 24v board........FRRRT!! Have a look in the manufacturers instructions,it will tell you in there what voltage stat you will need and it will show you how to wire one to your boiler should you be competant to do so. There are plenty on Fleabay or go into a reputable merchant, you can expect to pay anything from £20 (I picked 2 up on the bay at this price) to £100.
 
We have a combi boiler system with rads in each room, each with an adjustment valve. We have what I call a main control box in the living room, and it is set to 16C all year round, and we then adjust it manually on a daily basis, depending what the weather is like. So, we have not had to adjust it since March, and the rads have been off (the system has not kicked in). We find this the best way to save money, as our combined bill for gas/electric is now around £800 per year for a two bed semi.
 
The room stat really needs to be in an area not controlled by a TRV otherwise they may counteract each other.
 
john-oh said:
The room stat really needs to be in an area not controlled by a TRV otherwise they may counteract each other.
Click to expand...


Yes. I have just been thinking that.....

Thanks all for replies thus far.....
 
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john-oh said:
The room stat really needs to be in an area not controlled by a TRV otherwise they may counteract each other.
Click to expand...
Not quite sure how, the TRV may shut down the Rad,
but the thermostat will still be active, if the room is at temperature then it too will shut down, if not
it'll keep the boiler running.
If the rad, well that is boiler is shut down by the thermostat.
then the TRV cannot over ride it, as its not directly linked to the pump or boiler.
Just the heat the rad produces
 
Yes a Room Thermostat is a good idea and will help to reduce your fuel usage/reduce your fuel bills. All, RF thermostat receivers (switch)as far as I am aware, have 'voltage free' switch contacts for the boiler, so are suitable for either 240v or 24v, but you will need a 240v supply for the supply to the receiver. If you choose to fit it yourself, make sure that you connect it correctly as new PCB's for boilers are expensive.

The actual thermostat should be in a room with a radiator without a thermostat on, or just remove the head from the thermostatic valve, otherwise you run the risk of the TRV on the radiator 'fighting' with the room thermostat.

You might want to consider installing a programmable room thermostat to give you greater flexibility of control or one that you are able to control via the internet such as Hive, Nest, Owl or one from Honeywell or other control manufacturers.
 
Building regulations now state that you should have a room thermostat. People with more sense realise that one is not necessary.


Steve.
 
Steve Smith said:
Building regulations now state that you should have a room thermostat. People with more sense realise that one is not necessary.


Steve.
Click to expand...

People with more sense will see the benefit in having one.
 
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I think the idea of the room stat is to turn off the heating fully when the room is up to temp. With trvs most boilers still seem to run the pump for longer and noodle along firing up every so often. A room stat is an off off signal.

Its weird though as I thought most modern boilers had anti cycling features so they didn't keep going on and off again. Mine definitely keeps checking and circulating the water as I don't have a room stat. It is an antique though.
 
Steve Smith said:
I can't see the point. If you set your TRVs correctly. it serves no purpose.


Steve.
Click to expand...
The TRVs only control the flow to the radiators, whereas the roomstat actually controls the boiler. Having a roomstat means the boiler only runs for as long as it takes to get up to the required temp, then turns off, therefore saving gas/money.
 
Steve Smith said:
Building regulations now state that you should have a room thermostat. People with more sense realise that one is not necessary.
Click to expand...
If you don't have a room stat and have TRVs on all the radiators, then when all the rooms are up to temperature the pump will just pump the water around the bypass, because there's nothing to turn the boiler off. Assuming the boiler has a bypass.
 
onomatopoeia said:
If you don't have a room stat and have TRVs on all the radiators, then when all the rooms are up to temperature the pump will just pump the water around the bypass, because there's nothing to turn the boiler off. Assuming the boiler has a bypass.
Click to expand...

Until the boiler's internal thermostat turns it off.

With a roomstat, you can have a radiator in one room wanting heat but the boiler can't supply it as the thermostat in a different room has decided it doesn't need it.

Personally, I think it's silly to control the heat of a whole house based on the temperature in one room.


Steve.
 
We had that sort of system a few years ago, seemed to work just fine. Previous and present house have master stat and TRV. Tbh we turn the master way up and control the rooms using the TRVs. The master stat in present house is upstairs in the landing area, not fitted by me but seems the most illogical place to put it.

Matt
 
the only temperature control i ever use is the one on the actual combi boiler - this controls the water temp in the radiators and i normally have it set on only about 20% unless its cold but never had to go above 50% - also i only run the boiler when its actually cold enough to need it
 
Steve Smith said:
Until the boiler's internal thermostat turns it off.

With a roomstat, you can have a radiator in one room wanting heat but the boiler can't supply it as the thermostat in a different room has decided it doesn't need it.

Personally, I think it's silly to control the heat of a whole house based on the temperature in one room.


Steve.
Click to expand...
That's why the roomstat is usually installed in the hall. Your other rooms should beat up quicker than the hall, the trv's then shutdown the rooms that are warm enough, and when the hall is up to temp the boiler turns off. It's the most efficient way.
Without a roomstat, the boiler will either run longer than it needs to, or turn off before the house is warm enough.
 
If you need to keep the system running until the hall heats up, then I assume the hall radiator doesn't have a TRV. If it does, then this will be open calling for heat as the last room to get to temperature (although it shouldn't be if it were sized correctly). When all TRVs are closed, the boiler will shut itself off. It doesn't need a thermostat to do it.

I really can't see why you would use the temperature of one room to turn the whole system on and off whilst TRVs on other rooms' radiators are calling for heat.

If you are going to do that, you might as well get rid of TRVs and go back to fitting lockshield valves and see if you can remember how to set them up to get the right heat output from the radiator.

My father was a central heating system designer, my brother fits central heating and ground source heat pumps, I have fitted a few central heating systems and all of us and all the plumbers I know who have commented on it also don't see any point in a roomstat if you have TRVs on all radiators.


Steve.
 
The radiators should have a lockshield valve fitted, irrespective of whether a TRV or manual valve is fitted, to enable each radiator to be correctly balanced. Without a room thermostat fitted the boiler will cycle on it's own thermostat, wasting energy and money. When fuel was cheap, many years ago, the practice was to only fit TRV's, however, good installers nowadays recognize the benefits of room stats and TRV's.
 
Steve Smith said:
If you need to keep the system running until the hall heats up, then I assume the hall radiator doesn't have a TRV. If it does, then this will be open calling for heat as the last room to get to temperature (although it shouldn't be if it were sized correctly). When all TRVs are closed, the boiler will shut itself off. It doesn't need a thermostat to do it.

I really can't see why you would use the temperature of one room to turn the whole system on and off whilst TRVs on other rooms' radiators are calling for heat.

If you are going to do that, you might as well get rid of TRVs and go back to fitting lockshield valves and see if you can remember how to set them up to get the right heat output from the radiator.

My father was a central heating system designer, my brother fits central heating and ground source heat pumps, I have fitted a few central heating systems and all of us and all the plumbers I know who have commented on it also don't see any point in a roomstat if you have TRVs on all radiators.


Steve.
Click to expand...
Trv's won't turn off the boiler even if they are closed. The boiler will continue to pump water through the pipework until its own internal temperature sensor turns it off, which wastes energy. Also, the boilers internal temp sensor is measuring the temp of the water, not the room.
If a central heating system is sized correctly, and balanced, then all rooms should heat up fairly evenly time wise.
By having the roomstat in what should be the coldest area, it should be last to reach temperature, and the boiler turns off. If any of the other rooms are too warm by the time the boiler turns off, then turn down the trv in that room.
 
Steve Smith said:
My father was a central heating system designer, my brother fits central heating and ground source heat pumps, I have fitted a few central heating systems and all of us and all the plumbers I know who have commented on it also don't see any point in a roomstat if you have TRVs on all radiators.


Steve.
Click to expand...

really? or are you just trying to get a reaction? maybe your fathers design technology has moved on, your brother should know better and your plumbers opinions only reinforce the fact that there are heating engineers and then there are plumbers, one keeps you warm, the other is up to his neck in s***.
 
Well this has moved on a pace - I have elected to fit a room stat on the dining room and replace the TRV with a lock shield valve the dining room in my gaff is like an extension to the entrance way.

There is a lot of confusion about this and the new regulations seem to be being used by energy companies to tell people they NOW need a room stat .....
 
LASTOLITE said:
Well this has moved on a pace - I have elected to fit a room stat on the dining room and replace the TRV with a lock shield valve the dining room in my gaff is like an extension to the entrance way.

There is a lot of confusion about this and the new regulations seem to be being used by energy companies to tell people they NOW need a room stat .....
Click to expand...
Part L of the building regulations does state that a room thermostat should be fitted. This legislation has been around for a few years, so is not new.
Any company either replacing your boiler, or full heating system must ensure that the relevant regulations are met.
 
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Systems these days dont need a roomstat they actually have to have one and its now known as a boiler interlock... its purpose is to turn off the boiler when all rooms have reached temperature. All systems installed now should also have an automatic bypass (most decent combis have one built in)
I do see where Steve is coming from but it is now part of current legislation and for them to work properly it is essential to have correctly sized and balanced radiators.
 
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