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We have a towel radiator in the bathroom that is part of the central heating system. It worked fine last Winter.
When the heating went back on a few weeks ago, we noticed that it was only getting luke-warm (but uniformly so, no cold/hot spots) but the inlet pipe was hot below the TRV. I bled the radiator but very little air came out. I shut off all the other radiators to force a bit more pressure through this one, but no change. At this point, I assumed the TRV was stuck and only letting minimal ho****er through.
Fast forward to this morning and there was no hot water reaching the inlet at all. After about 2 hours of the heating being on the inlet pipe was starting to warm up.
Potentially, these are two separate issues. Can anyone shed any light on possible causes?
Cheers,
Paul
Rads blocked with silt so not allowing any water to flow around it hence no hot water getting to the inlet?
You can normally remove the thermostat bit from a TRV (it has a collar you can unscrew) - there's a sprung button underneath it. Try pushing the button up and down whilst the heating's running - it may just be something's blocking the valve.
If the system's been off, I'd suspect sludge build-up - when was the system last drained down? You could get someone in to do a power-flush or drain the system down, remove the towel rail and give it a good blast with a hose over a drain. Worth putting some corrosion inhibiter in the system. Be prepared for black sludge when you remove the towel rail
sticky valve. take the trv body off and work the sprung pin on the valve in/out a few times.
Would a sticky valve be preventing the hot water reaching the TRV? The hot water pipe to the rad was cold even after the heating had been on for a couple of hours.
I guess if there's very little flow through the rad, then the heated water can't reach that part of the system very quickly?
probably, but its a five minute job and would eliminate that. I've got some old radiators and generally have to free them all up at the start of the winter.
Make sure you haven't restricted the flow on the shield too.
If the water can't get out then it's not going to flow and get hot hence only heating up through conduction