1 cold radiator!

[M Forbes]

Hi everyone, I’m after some advice. I’ve tried 6 heating engineers but so far none have turned up so I have resorted to trying to have a go myself.

I have a radiator on a combi system which refuses to heat up. The pipe work and TRV valve heat but it won’t transfer into the radiator.

I have replaced the valves and checked there isn’t a blockage in the radiator. I have tried turning off other radiators to see if it’s a pressure / balancing problem but had no success.

Could this be an airlock? If so, what’s the best way to resolve?

Any help would be appreciated.

 

[JohnD]

turn off ALL the hot ones.

What happens?

 

[M Forbes]

The radiator still does not heat.

 

[AGAS]

take the trv head off and give the pin a couple of taps with back of spanner , spray some lubricant on pin and push it down a few times , if that doesn't work you need to get air out ,

 

[Elkato531]

He's already changed the valves.

What size pipes are supplying the rad? If you're on microbore and you've got a dirty system, a blockage is likely.

 

[dilalio]

Where is this rad located? Is it highest, furthest away? Is it fed by drops from above or piped from below. Is it connected to another rad?

If you can’t getting running by shutting all other rads down you could remove it and try flushing it though with hose pipe.
While it’s off, you could also connect a pipe between the two valves and see if heat flows through that.

 

[Madrab]

Can you bleed the rad and get it filled with water? If so warm the system up, then shut the rad down and take it off again. Keeping the system at over 1 bar whilst doing this, get a bucket, open each valve in turn and make sure each valve opens and water flows till it's warm & see if any air is expelled.

 

[M Forbes]

Checked TRV, it seems to be working. How do I get air out of system? I have bled the radiators. I have also drained the system and refilled but no success.

 

[M Forbes]

Hi Madrab, sorry just saw your post. I’ll give this a go when I get home tonight.

 

[M Forbes]

Hi Dilalio, the rad is in the dinning room (ground floor) with a combi boiler in the loft. The rad is fed from above using 10mm pipe.

I bought a new radiator and valves (the old ones were a bit tatty and could do with being replaced anyway) so there should be no blockages in the rad but this hasn’t helped.

 

[AGAS]

He's already changed the valves.

What size pipes are supplying the rad? If you're on microbore and you've got a dirty system, a blockage is likely.

When people say they changed the rad valves don't necessarily mean they are new valves ( new lock shield cover and Trv head ) customers use the old valves and install new rad because they isolate the system with said valves. Customers hey

 

[dilalio]

Hi Dilalio, the rad is in the dinning room (ground floor) with a combi boiler in the loft. The rad is fed from above using 10mm pipe.

I bought a new radiator and valves (the old ones were a bit tatty and could do with being replaced anyway) so there should be no blockages in the rad but this hasn’t helped.

Your 10mm is blocked - either flow/return or both... its on a drop and is where crud has collected. You can try some calchem in the system and concentrate it on that loop and see if it gradually eats away at the crud!

 

[M Forbes]

Hi Agas / Elkato531, thanks to you both for your comments.

I have indeed changed the valves (both TRV and lock shield).

The pipe is 10mm and so it’s possible there could be a blockage.

I’m going to have a go at Madrabs suggestion tonight. If that doesn’t work then I will have to perceive with the local professionals. Hopefully I can get someone to come out.

 

[M Forbes]

‘Persevere’.......auto correct and I obviously can’t spell