I have an unvented oil-fired system. Downstairs is underfloor, upstairs is wet rads. The problem is that when I have both downstairs and upstairs heating on, the rads are cold upstairs. When I turn the underfloor off, the rads upstairs get hot.
This is where a diagram of the system would paint a thousand words.I have an unvented oil-fired system. Downstairs is underfloor, upstairs is wet rads. The problem is that when I have both downstairs and upstairs heating on, the rads are cold upstairs. When I turn the underfloor off, the rads upstairs get hot.
So that rules out a design problem.It's been working fine for 7 years.
Sounds like there is still a path available, just no flow.The rads are completely cold apart from one or two that are lukewarm.
I've only ever seen a couple, but some manifolds have a small ball valve on each branch and if you turn off one valve on each loop it will restrict the flow through the UFH system as a whole.I haven't tried tempoarily turning off the loops (not sure how to do this tbh)
Those new symptoms do suggest that.Thinking about it, the hot water isn't as hot as it used to be and the radiators aren't hot hot, only very warm when I switch off the UFH. They used to be very hot, even when they were on with UFH and hot water. Sounds like it could point to a boiler problem?
You are correct - but I don't claim to be otherwise. Just a DIYer that takes an interest.Nb: this simonh2 fellow sounds a bit inexperienced, to put it politely.
The only stupid questions are the ones you don't ask - and so don't find the answers to.But why would rads be stone cold when UFH is on but some of them get hot when UFH is off if it was a pump issue?
I am completely ignorant by the way so forgive me if it's a stupid question
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