DIY Doctor UK DIY Forums

Hey Guys,

Hopefully one of you guys can help me here because both my wife and I are at our wits end! Our house is a mess and its getting near xmas!

I live in an 8 year old house and we have just coverted our garage into a playroom for the kids, but the radiator in the room refuses to work. The new radiator is connected by a T connector off the radiator that is just outside the playroom. The plumber that fitted it has tried various things but can get it to work. At one point it did heat up at the top and cold at the bottom.

Having read these forums i tried what was suggested in another post basically shutting off every other radiator in the house and left the new one open. Within 5 mins the new radiator was boiling, could hardly touch it. but as I started to turn the rest of them on again, the new radiator was almost cold.

The last thing the plumber did was empty the system but the radiator is still not heating. The radiator just outside the playroom was working before he drained the system, but is now not working.

Any help or suggestions that I could try will be greatly appreciated.

Many thanks in advance.

I am assuming the plumber knew what he was doing and this was not a diy job.

It’s either:

Pump, they have 3 setting and you should turn the pump to the max setting.

The boiler, its too small for the number of radiators you have.

They’re faulty trv or lock shields.

Some waste has got into the radiator or they’re an internal fault.

A fault with the pipe work

I don’t know how he attach the pipe work to the system, I think he may have just “tâ€

Thanks for your reply Peter.

The plumber is a young guy, but seems to know what he is talking about and he cant understand how its still not working.

And yes you are right to think he has "T" into the other radiator. He initially used 10mm white pipes (not the copper ones), but after it didnt work he striped it out and used 15mm pipes.

I have a Hercal indirect coil cylinder and its maximum capacity is 140 litres and I have 11 radiators in my house. Thats including the new one. Should that be big enough? I tried to find the pump to check if its on the maximum setting but cant find it.

I think I will need to get another plumber, hes now starting to avoid my phone calls. I have left 3 voicemails since last night and he hasnt contacted me yet. At least I havent paid him yet!

I could hear Peter chuckling to himself as I read the problem...Never a good idea to simply tee into an existing radiator. Not only that it would be a fine juggling act to get both rads to balance. another problem is that any adjustment to one rad would greatly affect the other. Pumped water will find the route of least resistance so the primary (original) rad will get priority feed and to tee off a 15mm feed with a 10mm gives the new rad NO CHANCE.. Don't pay the muppet and get a plumber in..

Sorry I have only just seen this reply.

Can you tell me what is the make and model of your boiler?

Very probably this is caused by using Speedfit pipe whilst the rest of the system is 15mm copper. Speedfit couplings need to have inserts in at the joints, and these reduce the bore, and hence the flow of water. You have proved the radiator is working but clearly, the water just prefers to go through other radiators rather than the new one.

The system probably just needs balancing to accommodate this new radiator so follow the instructions here.

[url]https://www.diydoctor.org.uk/projects/balancingcentralheatingsystems.htm[/url]

It could solve your problem without causing extra expense or grief!

Thanks for your advice guys.

The new radiator is now working fine. Adjusting the valves to slightly open on the other radiators as opposed to fully open seems to have done the trick with the new radiator at full blast.

Many thanks again.