Advice sought ...

[chrisn68]

I recently had a plumber install an additional 2 radiators (both 700x400) into my gas central heating system. Forgive me, but I'm not altogether technically minded, but I know that he took the supply for the new radiators from the pipes which supply a radiator (400x300) in the downstairs loo. The new radiators (which are just through the wall from the downstairs loo) do work fine but A) they take an eternity to heat up as opposed to every other radiator in the house which heats up almost instantly, b) they never get as hot as the other radiators and c) if the thermostat on the radiator in the downstairs loo is turned up beyond (setting) 2 it seems to affect the output of the new radiators quite considerably.

I'm not sure if it's significant but it's a new-build house (2 years old) with plastic piping throughout. The plumber didn't use the same piping for the new radiators which is, I think, 10mm, instead he used 15mm copper pipes which are considerably larger in diameter than those which feed the rest of the heating system.

Another thing I remember from when I got quotes for the work was that one bloke said something about the supply for the new radiators would need to come from a 'main' pipe as opposed to a 10mm pipe which feeds an existing radiator.

I've had the plumber back to see to the problem but he doesn't accept that there is one - mainly because the radiators he installed do work, which they do, but just not as well as I think they should.

I'm not sure what other information is required but the boiler is a GlowWorm Micron 60FF and it's a fully pumped system.

Any advice on this issue will be greatfully received.

Many thanks.

Christopher

 

[TicklyT]

Dont know if it is the complete answer, as there may be issues with pipe size, but it sounds like the system may benefit from balancing. Have a look in the FAQ sticky.
Basically it's throttling back the LSV's on the hot rads a bit and opening up the cool rads to encorage the flow to them.

From your point C) I would start by closing down the LSV on the small radiator in the loo, to say, 1 turn open, and see how that affects the new ones.

 

[denso13]

The pipe sizes are ok as is connecting into other rad as long as it isn't too far away (not ideal but ok).

As mentioned it does sound as if they need balanced. You could close off the other rads in the house to see if they work better.

 

[namsag]

In theory every rad on a microbore system should come from its own connection on the manifold or teed off seperately . The added resistance through valves etc will stop additional rads working properly. Your rads are not very big and balancing may help them heat up , but if it doesn`t get him back to do it properly.. I take it one of the guys who told you this when getting quotes did not get the work because he was dearer... Reason being he was doing job properly thus taking more time not making more money

 

[chrisn68]

Thanks for all your help and advice. Since last night I've had the valve on the downstairs loo radiator almost closed. So far, it's heating up fine (and I can even have it at setting 3!) and I've noticed a difference in the garage radiators already. I'll see how things go before getting him back again, but it looks like the balancing thing is the way to go to resolve the issue. Oh and Namsag you were right - the other bloke was dearer - a lot dearer. I've learned my lesson though