New radiator in loft causing problems

[jase158]

on the non return valve on pipework to radiator in loft, there should be an arrow, which way is it facing?

 

[Stevemarch1969]

on the non return valve on pipework to radiator in loft, there should be an arrow, which way is it facing?

Facing away from the radiator.

With HW only on all rads incl loft rad heat up!

makes me me think there is a problem with 3 port valve but why do all rads heat up except loft rad when ch selected on programmer but all rads incl loft heat up on HW?

 

[jase158]

Facing away from the radiator.

With HW only on all rads incl loft rad heat up!

makes me me think there is a problem with 3 port valve but why do all rads heat up except loft rad when ch selected on programmer but all rads incl loft heat up on HW?

is that pipe that you just turned off getting hot?

 

[lame plumber]

my question is what person wants to try heating a space in their roof lunacy in todays energy saving ethos

 

[Stevemarch1969]

Not hot no but warm

it used to be too hot to touch but I guess that was when the white valve was open allowing hot water to go straight into the return.

 

[jase158]

must be the 3 port valve, it may of just been the head that was replaced last time, may have gone wrong again or might just be poor quality.

 

[Stevemarch1969]

Whole of 3 port valve was replaced. It is a plumb center own brand about 12 months old. Not sure what they are like? Was done by a plumber.

why would ch only not heat the loft rad but HW heat it? Is this part of the 3 port valve fault?

 

[TBServices]

The cylinder return should always be the last connection to the boiler, or you will get flow down the ch return.

 

[jase158]

check valve not working or wrong way round, shut rad valves on loft rad, put hot water on only if no rads get hot then its check valve. if all rads still get hot then its 3 port valve. (not sure if you already done this). if it is check valve then maybe it has been manufactured incorrectly.

 

[Stevemarch1969]

This may well be the case as the boiler return is 22mm pipe and cylinder is 15mm so it must joint it somewhere.

thanks for your reply.