Firstly, please excuse my ignorance on this question. I have a temp controller in hallway (no TRV) 3 bedroom/ 2 living room/ 1 kitchen / 1 bathroom radiators all with TRV's numbered 1-5. All bedrooms and kitchen are set at 1 on TRV (hardly used) I have set my temp contoller in hall to 18.5. I've been told (by my housing association) to keep TRV's in living toom fully open (number 5) I've also been told (by a plumber) that number 3 would be best for the temp I set on the hall controller. Will having TRV at 5 not cost more? I'm really confused about this, and not just because I'm an older lady, I'm just confused as to how the temp controller and the TRV's work together. Any help would be grearly appreciated.
Temp controller (thermostat) will control the system and a TRV will control a radiator they are independant of each other. The thermostat will sense the temperature in the room that it is situated and swtch boiler off ( so rest of building won't get heated as a result) when the set temp is reached. Usuallythe thermostat will be in the coldest part of the building (but not always). A TRV reacts to the air temperature in each room, as the temp rises it actuates a valve to restrict the flow of hot water. The cost factor is totally dependant on your thermostat setting - higher setting = longer boiler operation to reach that temp and vice versa. If you feel that setting the thermostat at 18.5 is enough the maintain a comfortablew level of heat throughout then leave it at that. Another factor in controlling cost is boiler temperature setting, setting the central heating temp to 60c should be enough.
Thank you so much for your speedy reply to my query. If I understand correctl (or not!), the TRV's cannot override the temperature set on the controller, the numbers on the TRV relate solely to restricting/allowing the flow of hot water. According to what I've been told number 3 on TVR = approx 18-20 degrees, 4 = approx 20-22 degrees and 5 =22+. I think this where I get lost, If I've set temp controller in hall to 18.5 (which I do find quite comfortable) do I use the TRV's to correspond to that temperature (for eg number 3 on TRV) or do I just have them on number 5-fully open and they'll cut off anyway when temp is reached? Can I ask another silly question? If it's all down to the temperature set on the controller (18.5 ) why do I need TRV's?? Would the controller not just close down when 18.5 is reached and come on again if temperature drops? End of silly questions, I do apologise.
The controller switches the whole system on and off, depending on its settings including temperature, if this was the only control rooms would be too cold or too hot. The TRV's act independently of the controller and allow you set the temperature in each room. This also saves money because you're not heating rads unnecessarily Normally the controller temp shut off temp will only be reached after all other rooms are warm enough.
You need TRVs as the room they are controlling may well go over temperature before the hall, where the controller is, reaches 18.5. So if the living room, for example, reaches 18.5 before the hall and you have the TRV in that room set to a comfortable setting (requires a modicum of experimentation to get the TRV setting right) it will shut off rather than continually blasting out heat while the hall heats up to 18.5 so saving gas. Hope that makes sense! Also, of course, you can turn the TRVs in unused rooms down to 1 or the frost setting. The rest of the rooms will heat up quicker as you are not pumping water through the unused rooms' radiators, so also saving gas. The fewer radiators you have on, or which have closed off due to them reaching their setting, the quicker the hall will heat up to the temp on the controller so shutting off the boiler completely, if that is where the controller is.
I've finally got it (you'll be glad to hear) and at last I understand how the temp controller and TVR's work. Many, many thanks for the replies, I only wish I'd discovered the forum earlier. Than you again.