It's that time of year for central heating woes.

[80Sprint]

Central Heating worked fine last year and no changes except radiators would sometimes get warm when the heating was off so we shut down the valve on each. Done that in previous years and all ok.
Heating turned on last week and all radiators hot except the bathroom towel rail.

I thought it may be a balancing issue as the valves were off as my wife just opened them up again. I shut them all off again and just left the bathroom rail open. Still no heat in it but strangely we still had some hot radiators in the house that were turned off at the valve.

My thoughts were, faulty radiator valve on the ones still getting hot and not letting the system balance but I can't see that being the case on more than one radiator. Or, towel rail valve faulty and not letting flow through.

Any other thoughts before I start taking things apart ?

I assume the fact that the radiators get hot in the summer is that it could be a faulty 3 way valve but not sure if that would have an effect on the first issue ?

[new to this]

I would say the bathroom radiator valve is faulty,if you have thermo static valve fitted some times the centre pin gets stuck,take the top of and your see the centre pin spray WD40 over the pin may clear your fault,other wise its a replacement valve needed

Dave

[Flyfisherman]

Mike

the bathroom - if its hot at the bottom and cold at the top, air is trapped and it requires bleeding. There should be a little squared headed screw on one of the ends, open this up to release the trap air. Might be worthwhile opening all the rad thermostats to max and bleed all the rads.

Paul

[Jod Clark]

Yes, a faulty three port valve will cause the radiators to get hot in the summertime.

Sounds like the flow to your towel rail is being restricted somehow, plus some other valves are passing. I'd drain the system down, remove the radiators and flush them out thoroughly (same technique as a car radiator is fine) A trade pack of radiator valves isn't that expensive, I'd remove the existing ones from the rads that are getting hot wen the valves are shut, and replace them. You can almost always get away with using the existing olives on the rising pipes as they don't have much pressure behind them.

Refill the system with a good corrosion inhibitor and, if you're really keen, use rainwater rather than tapwater to really minimise silting in future.

[oily66]

The problem is with shutting off the valve, sometimes the seal inside it sticks closed from over tightening.
It needs to be closed enough to stop the flow not until the valve is rock solid, just like your basin taps.
I run mine up to temp through the summer at least once a month to keep it fresh, bit like air con really "use it or lose it"

[GTS290N]

Move to Scotland.
Your heating will be on all year round, problem solved.

[80Sprint]

Thanks guys. A sticking valve. A does of WD and a tap sorted it.

The summer issue may be another story as I have found two motorised valves but they are both 2 way, not 3. Something for next spring maybe.

[Jod Clark]

Are they Sunvic motorised valves, with a little red thumbwheel on the side of the motor head?

[Karlos]

Be careful if you are bleeding a system. I have a combination boiler with a mini internal 10lt preheat tank. The tank has a bladder in it to also regulate the system pressure. I had an additional radiator fitted and the guy who drained the system did not check the boiler type properly so the pressure regulating bladder burst in the mini tank. He should have released the pressure in the bladder first,there is a schrader valve on to of the boiler. Cost us £250 to get a new one fitted.

[Karlos]

It also cost a few cold nights too.

[80Sprint]

No Jod, they are silver boxes with a lever to switch to manual. If these are only in and out, does that mean the heating is totally separate. I have a small water tank in the loft for the heating and a boiler in the kitchen.

[new to this]

No Jod, they are silver boxes with a lever to switch to manual. If these are only in and out, does that mean the heating is totally separate. I have a small water tank in the loft for the heating and a boiler in the kitchen.

Yes by fitting the two valve's, you will have better control of your heating,

Dave