Fitting thermostatic radiator valves

[Slinky]

How difficult is it? Got seven radiators in the house, none of which are thermo valves, thermostat is downstairs so the downstairs rooms get to the right temperature and upstairs is like an oven!

Any thoughts or suggestions folks?

W

[Yuxi]

Very easy, just dont buy the really cheap ones from B&Q, I bought 4 about 2 years ago and have replaced 2 because they started to leak.

[Gingerbread Man]

You have to drain the system down to fit them.

Undo the nut connecting to the rad and then the copper pipe.

Cut the copper olive off (hacksaw). Fit the new TRV.

Hold the TRV as you tighten and loosen the fitting with grips. Otherwise it can twist and bend the pipe.

[King Herald]

Slinky said:

How difficult is it? Got seven radiators in the house, none of which are thermo valves, thermostat is downstairs so the downstairs rooms get to the right temperature and upstairs is like an oven!

Any thoughts or suggestions folks?

W

Fitting new ones is fairly straightforward, from what I saw last month when someone did ours. You need to double check your thread and pipe sizes too.

Apparently some old valves can be a real ball ache to remove, (prior to fitting your TRV) as sitting in water for twentyten years produces a fair amount of rust in the thread, if the system had never been treated. Big wrenches and blow torch heat were mentioned by our plumber guy.

[Poverty]

can be done without a drain down, however would be safer for you. Radiators, if old will probably need their tail pieces updating, (the bit that connects from the rad to the radiator valve.

[Yuxi]

If your radiators are fairly new you should be able to re-use the existing olive and nut on the new TRV. I did.

[King Herald]

Poverty said:

can be done without a drain down, however would be safer for you. Radiators, if old will probably need their tail pieces updating, (the bit that connects from the rad to the radiator valve.

An old guy changed our divertor v/v without draining down. I fully expected ten gallons of black gunge to pour out all over him when he undid the pipes, but nary a drop fell out.

Something to do with plugging the outlet to the header tank I believe.

[Poverty]

King Herald said:

Poverty said:

can be done without a drain down, however would be safer for you. Radiators, if old will probably need their tail pieces updating, (the bit that connects from the rad to the radiator valve.

An old guy changed our divertor v/v without draining down. I fully expected ten gallons of black gunge to pour out all over him when he undid the pipes, but nary a drop fell out.

Something to do with plugging the outlet to the header tank I believe.

yeah he just bunged the system. Plugged the feed and expansion pipes to make an air lock of sorts.

If its a combi or sealed systm just relieve the pressure and its all good.

[Tunku]

TRVs like TVRs are very good. If like me you have a roaming radio controlled thermostat, make sure the TRVs are turned up high when your thermostat is in the vicinity for a good while. Otherwise it gets either hot or cold in bits you wouldn't think of.

[GreenV8S]

Tunku said:

roaming radio controlled thermostat

A what?

[parapaul]

GreenV8S said:

Tunku said:

roaming radio controlled thermostat

A what?

I have no idea! But I have a mental image of a standard room 'stat, controlled by Tunku with the same sort of remote used for RC cars, helicopters etc., buzzing around the house, bumping into doorframes and getting in people's hair...

Am I close?

[thinfourth2]

Before you fit the new ones goes round the rads and find out which end the hot water comes in as older TRVs can only be fitted on one side and the newer ones you need to set to the correct flow

[Flashheart]

To do it without draining the system go to screwfix.com and buy item 81203 (£14.99). It's a set of bungs which you shove into the feed and overflow pipe in your header tank. It creates a vacuum so you should be able to do it with very little water loss. However....

I would use this as a perfect excuse to clean the whole system. Add some system cleaner before you start and follow the instructions (usually run it for a day or so). Then drain the system down. As you disconnect each rad to put the new TRV on, lift them off the wall, take them outside and put a hosepipe on one end and flush all the rubbish out. Fit your TRVs, connect it all up and then put some system protector in and hey presto, almost a new heating system. Allow the best part of a day to get the job done.

[Incredible Sulk]

Gingerbread Man said:

You have to drain the system down to fit them.

Undo the nut connecting to the rad and then the copper pipe.

Cut the copper olive off (hacksaw). Fit the new TRV.

Hold the TRV as you tighten and loosen the fitting with grips. Otherwise it can twist and bend the pipe.

Is there a secret to cutting the old olives off without marking the pipe?

If there is, I haven't discovered it!

[tlracing]

Flashheart said:

Allow the best part of a day to get the job done.

i.e. Good opportunity to get spanners, wrenches and other manly items out and undo things! Much better for a bloke than going to the supermarket/garden centre/mother-in-laws...

[thinfourth2]

Incredible Sulk said:

Gingerbread Man said:

You have to drain the system down to fit them.

Undo the nut connecting to the rad and then the copper pipe.

Cut the copper olive off (hacksaw). Fit the new TRV.

Hold the TRV as you tighten and loosen the fitting with grips. Otherwise it can twist and bend the pipe.

Is there a secret to cutting the old olives off without marking the pipe?

If there is, I haven't discovered it!

Pointless anyway as the pipe underneath will be slightly crimped by the old olive so you have way less chance of it actually gripping and sealing

[Incredible Sulk]

thinfourth2 said:

Incredible Sulk said:

Gingerbread Man said:

You have to drain the system down to fit them.

Undo the nut connecting to the rad and then the copper pipe.

Cut the copper olive off (hacksaw). Fit the new TRV.

Hold the TRV as you tighten and loosen the fitting with grips. Otherwise it can twist and bend the pipe.

Is there a secret to cutting the old olives off without marking the pipe?

If there is, I haven't discovered it!

Pointless anyway as the pipe underneath will be slightly crimped by the old olive so you have way less chance of it actually gripping and sealing

So what to do then? Graft in a bit of new pipe from underneath the floor up to the radiator?

I'm just about to have a go at replacing one of my TRV's that has died of old age, so I would like to know what I'm letting myself in for before I take anything to bits!

[thinfourth2]

Incredible Sulk said:

So what to do then? Graft in a bit of new pipe from underneath the floor up to the radiator?

I'm just about to have a go at replacing one of my TRV's that has died of old age, so I would like to know what I'm letting myself in for before I take anything to bits!

I would be surprised if the nut and olive off the old valve doesn't fit the new valve as the thread standards have been in place for fecking ages

[dirkgently]

thinfourth2 said:

Pointless anyway as the pipe underneath will be slightly crimped by the old olive so you have way less chance of it actually gripping and sealing

They will only be crimped if some monkey without a clue has been swinging on the spanner.

Incredible Sulk said:

Is there a secret to cutting the old olives off without marking the pipe?

If there is, I haven't discovered it!

If you can spare £15 you can bye an Olive cutter

[fatboy b]

I changed ours 3 years ago on a house built in 1982 with £4.99 jobbies from Screwfix. Took me and my brother about 2 hours to drain down and swap the valves on 11 rads - leaving the hallway one by the room stat. I reused all the olives, so never had to cut them off. Never had any problems, though have since replaced two bathroom rads, and the plumber doing it recomended that the TRVs were left off those.