New Rad getting warm when Hot Water on

[moosekat]

Hi Guys.
I have just had a loft conversion built, and hopefully finished by the weekend. As part of the work we had a new unvented cylinder installed in the attic ( same floor as the loft rad) with the boiler still on the ground floor. I have just noticed that the new radiator in the loft is warm, whereas all the other radiators are cold. The only thing is that the hot water has been on. We have not had heating on at all.

What could be causing this?? Any ideas?? I have a plumber coming but wanted to know what it could be.

Thanks.

Nick

 

[gas112]

teed into wrong place

 

[CBW]

I have a plumber coming but wanted to know what it could be.

Is this the same plumber who installed the unvented cylinder?

 

[moosekat]

Yes same plumber. He left pipes for the builders to add the radiators to. They then installed the radiators. I know nothing about heating systems, but could they have hooked the radiator to the hot water system?? Is that a possibility?

 

[moosekat]

teed into wrong place

What does that mean?? I know absolutely nowt about heating.

 

[CBW]

Yes same plumber. He left pipes for the builders to add the radiators to. They then installed the radiators. I know nothing about heating systems, but could they have hooked the radiator to the hot water system?? Is that a possibility?

Why are builders installing the radiators and not the plumber? Yes anything is possible if people don’t know what they’re doing (not saying it’s the builders, but someone has messed up).

 

[moosekat]

Why are builders installing the radiators and not the plumber? Yes anything is possible if people don’t know what they’re doing (not saying it’s the builders, but someone has messed up).

The unvented cylinder was installed 6 weeks ago while the floor was up etc, and they installed the rad after the plastering etc was complete.

 

[CBW]

Well if it’s only heating when the hot water is being heated then it’ll be as per @gas112 - the tee has been installed in the wrong place - your plumber should be able to sort it out.

 

[ianmcd]

The return connection from your HW cylinder has to be the last connection in the circuit, if not this will happen

 

[gas112]

What does that mean?? I know absolutely nowt about heating.

the plumber you have coming will know what to look for should only take him minutes to confirm

 

[moosekat]

So I just tested the system again. Turned off the hot water (all rads were cold) and turned on the heating. All rads including the loft one is getting hot.

So does this mean it is plumbed in correctly? Can 1 rad get hot on both hot water and heating?

To test my theory the hot water only comes on tomorrow morning. I will test the rad then to see if it is warm.

 

[gas112]

yes it can get hot with both on .
From stone cold in the morning when you turn just the hot water on after a few minutes feel the pipe coming from the heating motorised a couple of feet away from it and it should not be warm that confirms valve is not passing slightly

 

[moosekat]

So this morning the rad did get warm with the hot water being on. Spoke to my plumber and he thinks a non return valve was not fitted when the builders added the additional pipework and rads. He is going to pop by and fit one. Does that sound correct??

 

[gas112]

nope totally wrong
did you feel the pipe past the motorisded valve ?

 

[moosekat]

nope totally wrong
did you feel the pipe past the motorisded valve ?

So what would you look at if it is getting