New radiator fitted- stone cold radiator and pipes

Fogle1980

Hi, we had 2 new rads, 1 upstairs and 1 downstairs fitted yesterday. The one new rad downstairs which is always the last to heat up now won’t work at all. He drained each one individually when replacing,  not the whole system.

The plumber shut off all the valves upstairs and the cold rad downstairs went luke warm at best with all of the others downstairs very hot.

The plumber says there may be a build up in one of the pipes and he may need to remove floorboards to get to pipes.

I also got the impression we’d have to pay extra for this. 

Has anyone got any other suggestions to resolve and is he right in saying we should have to pay extra? His quote for the radiators was a small fortune. 

bob_a_builder

Why were those 2 changed ?
Working fine before change?
Are the feed pipes to the new Rads Hot ?
Try turning ALL the radiators off, except the 2 new ones - and maybe try them one at a time too so the full flow is just going to one rad at a time

Albermarle

What speed is the pump set at, there are usually 3 possible settings? Normally it is on the middle, see if putting on the fastest setting helps.

Fogle1980

Yes feed pipes cold, when the downstairs rad went luke warm the feed pip was very hot

FreeBear

Albermarle said:

What speed is the pump set at, there are usually 3 possible settings? Normally it is on the middle, see if putting on the fastest setting helps.

The pump should be set at a speed to suit the system - This is often the lowest speed. Modern pumps may also have an adaptive setting to vary the flow rate as TRVs activate.

Fogle1980 said:

Hi, we had 2 new rads, 1 upstairs and 1 downstairs fitted yesterday. The one new rad downstairs which is always the last to heat up now won’t work at all. He drained each one individually when replacing,  not the whole system.

The plumber shut off all the valves upstairs and the cold rad downstairs went luke warm at best with all of the others downstairs very hot.

The plumber has probably failed to balance the system properly. To do it effectively, you (the plumber) needs to measure the temperature at the inlet and outlet pipes and adjust the lockshield to get the correct temperature drop (typically 10-12°C). If he has just done it by ear or feel, he needs a kick up the backside.

In the absence of any suitable thermometers, I'd suggest cracking the lockshields on the cold/warm radiators open slightly - An eighth or quarter turn at most. The very hot ones could benefit from being turned down slightly.

Fogle1980

FreeBear said:

Albermarle said:

What speed is the pump set at, there are usually 3 possible settings? Normally it is on the middle, see if putting on the fastest setting helps.

The pump should be set at a speed to suit the system - This is often the lowest speed. Modern pumps may also have an adaptive setting to vary the flow rate as TRVs activate.

Fogle1980 said:

Hi, we had 2 new rads, 1 upstairs and 1 downstairs fitted yesterday. The one new rad downstairs which is always the last to heat up now won’t work at all. He drained each one individually when replacing,  not the whole system.

The plumber shut off all the valves upstairs and the cold rad downstairs went luke warm at best with all of the others downstairs very hot.

The plumber has probably failed to balance the system properly. To do it effectively, you (the plumber) needs to measure the temperature at the inlet and outlet pipes and adjust the lockshield to get the correct temperature drop (typically 10-12°C). If he has just done it by ear or feel, he needs a kick up the backside.

In the absence of any suitable thermometers, I'd suggest cracking the lockshields on the cold/warm radiators open slightly - An eighth or quarter turn at most. The very hot ones could benefit from being turned down slightly.

Thanks for your feedback, so should I just turn the valve to the left/right very slightly on the cold one? I presume it’s fully open atm

FreeBear

Fogle1980 said:

FreeBear said:

Albermarle said:

What speed is the pump set at, there are usually 3 possible settings? Normally it is on the middle, see if putting on the fastest setting helps.

The pump should be set at a speed to suit the system - This is often the lowest speed. Modern pumps may also have an adaptive setting to vary the flow rate as TRVs activate.

Fogle1980 said:

Hi, we had 2 new rads, 1 upstairs and 1 downstairs fitted yesterday. The one new rad downstairs which is always the last to heat up now won’t work at all. He drained each one individually when replacing,  not the whole system.

The plumber shut off all the valves upstairs and the cold rad downstairs went luke warm at best with all of the others downstairs very hot.

The plumber has probably failed to balance the system properly. To do it effectively, you (the plumber) needs to measure the temperature at the inlet and outlet pipes and adjust the lockshield to get the correct temperature drop (typically 10-12°C). If he has just done it by ear or feel, he needs a kick up the backside.

In the absence of any suitable thermometers, I'd suggest cracking the lockshields on the cold/warm radiators open slightly - An eighth or quarter turn at most. The very hot ones could benefit from being turned down slightly.

Thanks for your feedback, so should I just turn the valve to the left/right very slightly on the cold one? I presume it’s fully open atm

Clockwise to close, anticlockwise to open.

The lockshield will be on the other end of the radiator to the TRV - Usually hidden by a plastic cap that pulls off.

Fogle1980

Clockwise to close, anticlockwise to open.

The lockshield will be on the other end of the radiator to the TRV - Usually hidden by a plastic cap that pulls off

Thanks I’ve  located the valve. Surely the plumber would have fully opened it yesterday, I don’t want to try and turn it’s already fully opened and break it. 

FreeBear

Fogle1980 said: Thanks I’ve  located the valve. Surely the plumber would have fully opened it yesterday, I don’t want to try and turn it’s already fully opened and break it. 

The lockshield is there to restrict the flow of water through the radiator giving time for the water to give up the heat. Very, very rarely does the lockshield need to be fully open - On my radiators, most are open by half a turn or less.

Veteransaver

Have the new radiators been bled of air? If they are completely full of air they won't get warm at all

Fogle1980

Yes he’s bled the new ones I’m told. I might try the lockshield…it’s so frustrating!