Upgrading my system to use TRVs - Couple of queries...

[Chris_J]

Hi everyone.

I've had a good search on the forum about TRVs and found some very useful information, but I have a couple of questions.

My current system is a 24kW combination boiler running 8 radiators. The only temperature control I have in the whole house is the one located on the boiler pannel - which works well, but needs a lot of adjustment. All the radiators have standard manual spindle valves with lockshield valves and there are no room thermostats.

Obviously, this isn't the most energy efficient system, so I'd like to better it by fitting TRVs.

All my radiators are fitted with those angled standard chrome compression valves (PVC pipework) as per the picture below:

1. Does this valve have to be removed completely to fit the TRV or can the spindle and olive on my current valves be removed and the TRV fit into that? I'd like to fit something similar to the one shown below:

2. I understand that one radiator should not have a TRV fitted and be left wide open to act as a bypass. Is there any radiator in particular which should be chosen as the bypass? Maybe a radiator located in a warmish room (bathroom) to keep it from firing the boiler up all the time..?


3. Once I've fit the TRVs, what is the best way to set the temperature on the boiler? Should I set the boiler on full and let the TRVs do the work, or should I be adjusting both?

Cheers guys.

Chris.

 

[Rob]

You need to drain the system and replace the whole valve.

Fitting TRVs is a very good idea and would work even more efficently if you fiitted a room stat to the system usually in the lounge or hallway.

This is then the room you leave without a TRV and also can act as a bypass.

If you cant hard wire a roomstat then radio frequency ones are available and can be sited practically anywhere suitable


hope this helps!

 

[Chris_J]

Cheers for your reply rob.

Once you've kitted out your house with thermostats, is the boiler best left at full power so it can heat the room up to temperature in a shorter period of time and therefore spending more time switched off?

 

[WelshBoa]

Thats the way I have done mine, three quarters way up. The way I figure it is the quicker the rads get hotter and up to the room stat temperature the quicker the boiler can turn off. There may be a more scientific reason to not do it this way.....dont think so though.

Obviously if you have TRV's but no room thermostat the boiler will be on constantly anyway during the heating period set. The rooms may be cooler according to the TRV's but all the heat will then be going through the outlet radiator without one.

 

[bengasman]

First step: roomstat in lounge, 2 lockshield valves on lounge rad
Put trv on all other rads, preferably on flow.
If the pic really is your kind of valve, replace them as it is a cheap nasty model.
Rad in lounge does not need to be fully open, but balanced like all the others.
And don’t forget the inhibitor when you fill the system

 

[Chris_J]

Some good advice there, cheers.

I won't be able to fit a wired thermostat, so I will be going for a wireless RF one. Are these systems universal and easy enough to wire up to any boiler, or do I need to check my boiler is capable of having a thermostatic control?

Also, my lounge is often quite cold, despite BOTH raditors being on full. The reason for this is that I have exposed wooden floors, so there's always going to be cold air coming up from under the floor. Since this room is going to be colder than average (unless I have the wood burner going) it may not be the best of places to locate a room stat. Would it be better placed in the hall maybe?

Yeah, the top pic shows the type of valves I have, both as the temp adjustment and the lockshields. Are these valves particularly bad or something? Haven't had much trouble with them, except a few were weaping slightly from the spindle, but nipping them up stopped it.

 

[twgas]

dont put roomstat in lounge if you've got a wood burner as when you use it, it will turn off the r/stat and the rest of the heating may not have had time to heat house properly, hall is a better option.