Newly installed Radiator cold...

[worz]

Hey all some advice needed please.

I just installed a new radiator, replacing an old one, but I had to do a bit of new pipework, valves etc.

This rad is not getting hot, there is water in the rad, the feed pipe up to my valve is red hot, but the rad itself is not getting hot?

Any ideas on what is the most likely cause please. Solutions would be good too

I guess faulty valve, or possibly a blocked flow pipe (not sure if thats what it is called).

I would like some ideas before I have to drain the whole lot down again.

Many thanks

Worz

 

[dextrous]

Is the TRV bidirectional?

 

[worz]

I just used old fashioned valves.

Worz

Maybe I should

 

[JayJay1978]

If both valves are open and the rad is bled then its probably an airlock, crack open the union on the return and into a tray or wet vac to restore flow.

Even easier if a drain off valve is fitted.

 

[worz]

I shall give that a go right after lunch

Thanks

Worz

 

[morrissey86]

Check flow valve is fully open, and vent all your radiators. Especially the one thats cold do this a couple of times. and then see if radiator heats up. Also see if there is enough pressure in system ie of filling loop from the boiler ok.

 

[worz]

hmmm, with most of the rads in the house turned off, this rad now warms up after following jays advice, it doesnt get really hot to the touch like the other few i left on do?

I have now turned all back on, and the dodgy rad is not heating up anymore. I have bled all rads, most didnt need it.
When I turn the others on, they get hot almost instantly and i can really hear the flow through them.

Morrissey.. When you say vent, do you mean bleed?

There seems to be plenty of pressure, as all others in house are fine.

One last thing, when i installed the new rad, in a slightly different position from the old one, i had to use a couple of elbows in the pipework, this isnt going to make that much difference is it?

Cheers

Worz

 

[JayJay1978]

Do you have any microbore pipework in your system? (thin heating pipe of say 8mm?) this can cause stubborn airlock.

What I would do in your situation is this.

1. Turn both rad valve off
2. Remove rad
3. Open both valves into container until it flows free.

What system have you got? Open vented or sealed?

 

[worz]

Jay.... No microbore that I am aware of. The feed and flow seem to be mainly 22mm going down to 15mm near this dodgy rad.
Its open vented I think that's what its called, has a header tank.

Thanks again

worz

 

[StevenJames]

Did you make sure that the flow and return from the cold radiator are connected to the flow and return and not both to the return?

You can try turning off all the hot rads (manual/trv valves) and forcing any air into the cold rad, and then venting it.

Is the system correctly balanced?

Does it heat up at all ie lukewarm slightly? If so, it could be tee'd off in 15mm and needs more 22mm pipe close to it

Also is the rad bigger than a previous one? Burner pressure may be not set high enough if you have a range rated boiler, but then again this would affect not just 1 rad.

 

[worz]

StevenJames...

I just used the pipes that fed the existing rad, just had to add a bit of pipe to move to the new position. The old rad used to heat up ok.

It wont be correctly balanced as I have been turning everything off and on to try and force air or hot water into the affected rad. Mind you it doesnt exactly get boiling hot, as the others do when it is the only rad on!

It does get ever so slightly warm and it is tee'd off of the 15mm pipe, however this is only a foot or two along from the 22mm.

I am just waiting for the water to cool down when I will try Jays suggestion.

But any further info welcome.

 

[StevenJames]

What type of rad is it? Some rads don't give off very much heat, especially designer type rads...

 

[worz]

No its not that, its a 'myson he' I have quite a few and the others are to hot to touch!

 

[StevenJames]

is the trv head on correctly and the pin operating fully? Is the lockshield open enough?

 

[worz]

No TRV's just normal valves.

I did as Jay suggested and removed rad.

Should i get flow from both sides? the what i think is flow flows freely but the other side?(gets hot) just tricles unless the pump is running?

Thanks again

Worz