New radiator in loft causing problems

[Stevemarch1969]

Apologies, reposted in central heating forum.

 

[Stevemarch1969]

i did not ask my Q correctly
If you select CH only does boiler works and you get CH , or do you have to have hot water selected at the same time to have Ch running ?

I can select either hot water or central heating separately or both together on the programmer.

Steve

 

[SafeGasInstall]

so you have a 3 position 3 port valve

 

[Stevemarch1969]

so you have a 3 position 3 port valve

Great, thanks for that.

So best option is to take flow for rad before 3 port valve as if I do it HW side it will only work when HW on.

It is currently connected to ch side of the 3 port and does not work when ch selected though so maybe this option will not change anything?

I assume also the return from the hot water cylinder is separate from the rad return system (although they may join further down the pipe)

Steve

 

[SafeGasInstall]

i think piping it to after the 3 port on the Hw side will be your best option or
have it piped as a bypass radiator and it will be on at all the time and then secondary control will be your thermostatic radiator valve

 

[Stevemarch1969]

i think piping it to after the 3 port on the Hw side will be your best option or
have it piped as a bypass radiator and it will be on at all the time and then secondary control will be your thermostatic radiator valve

Bypass radiator sounds good as HW side would mean only on while demand for hot water on.

How is a bypass radiator piped and how does it work please?

Cheers

Steve

 

[SafeGasInstall]

as mention before by MJ ,
flow from before 3 port valve and return back to return pipe

 

[Stevemarch1969]

as mention before by MJ ,
flow from before 3 port valve and return back to return pipe

Brill thanks.
Only thing I'm not sure about is the fact that at the moment the radiator doesn't work when ch only selected since the one way valve has been fitted on the return.( It must have worked before this was fitted by being filled from the return?)The return pipe however is red hot. It's as if the water in the return is preventing the rad from flowing correctly if that makes sense.

Steve

 

[SafeGasInstall]

I think your plumber has messed things up , as there is no way return pipe to be hotter then flow pipe unless pipes are been crossed over or secondary circulation has been present before work started , pls post some pictures as it gets complicated or list location for a trusted plumber to visit and sort it out for you

 

[TBServices]

Daft question, is there a chance he's used a directional TRV and put it on the wrong side of the rad?

 

[Stevemarch1969]

Daft question, is there a chance he's used a directional TRV and put it on the wrong side of the rad?

Thanks for reply.

Trv is fitted to return side and is ecocal.

it does get some heat in it when on HW only.

Steve

 

[SafeGasInstall]

or nrv wrong way around ?

 

[SafeGasInstall]

or NRV is faced wrong way

 

[Stevemarch1969]

or NRV is faced wrong way

Just done a little test.

loft rad off at Trv all other radiators ok.(ie not hot)

as soon as Trv switched on on loft rad, other rads below get red hot but flow and return of loft rad are not hot and loft rad not hot. When loft rad on, return pipe with Trv on gets hot but only up to one way valve which stops it entering system.



steve

 

[Stevemarch1969]

TRV is on return side and has one arrow pointing into rad and one pointing down at return pipe.

NRV is on return pipe and allows flow away from rad only.

other side of rad has standard lock shield.

 

[mfgs]

Sounds like it is definitely piped wrong, lots of possibilities as to what he has done. Best thing is to get him to do it again from scratch, there will be no need for any non return valves when pipes correctly.