rads not heating

Leilak

I put the heating on tonight, first time since May and nothing! boiler ignites but dosent heat the rads, same thing happened last year after summer but I got it going after following a tip online but I cant remember what it was, the water is heating fine. would anyone have any tips how to get them on?

slapper999

Rads could need to be bled, meaning air let out of them.

Do you have a separate switch for hot water and heating?

Is there a small lever in your hot press to switch from hot water to heating?

Skatedude

Also try turning off all the rads, then turn on one at a time starting with the downstairs ones and allow it to warm up a bit before turning on the next one.

It does sound like the system is airlocked, so probably needs to be topped up and bled.

Jimbob1977

If you have an oil tank, it could be airlocked if it is almost empty of fuel.

Probably the radiators simply need to be bled with a Bleed Key. There will be a release of air and then the water will flow. Keep a cup handy for the water that will flow out and then lock it again.

It could be that a radiator in the middle of a series is blocked. It's trial and error. There will be a very satisfying rattling and release of air when you isolate the offending radiator.

I'm not an expert, but most houses have a small tank in the attic called a Feed and Expansion tank. If there is a lack of water, it can be a problem.

K.Flyer

Leilak wrote: »

I put the heating on tonight, first time since May and nothing! boiler ignites but dosent heat the rads, same thing happened last year after summer but I got it going after following a tip online but I cant remember what it was, the water is heating fine. would anyone have any tips how to get them on?

If you have no heat whatsover in your radiators it is unlikely that venting (bleeding) them will have any effect. This is usually done when a system has been emptied and is being refilled or when one or a few radiators are not heating up or are only partially heating at the bottom and the top of the rad is cold.

O.P.
If your boiler is functioning and producing hot water then...
First check if your room stat is turned up enough, ensure all rad valves are open. Check if you have an electronic zone valve and that it is operating, or check that you may have a heating circuit isolation valve and that it is in the on position. Its usually in the hot press.
Do you have a timeclock that heats hot water and rads seperately? If so, try the heating in the "constant on" position.

Paullimerick

Sounds very like to me that the circulating pump for the heating is stuck. To Un free it u will need two flat screwdrivers. One to open screw on pump and the second smaller one. You put it in where the big screw came out. Keep turning till u feel it enter a groove inside. Then turn it a few times left and right. All this with the heating turned on. When it goes you will feel it like putting the screwdriver against a fan. Then replace big screw and enjoy the heat.

slapper999

Paullimerick
The OP's hot water is heating so the pump must be pumping the hot water through the coil in the copper cylinder to heat the water.

youtube.com/watch?v=q7ncVld1Yyw

Paullimerick

Slapper999
Do u know the system. Is there one or two pumps. Anyway just gave my opinion of what may be wrong.

Leilak

its gas not oil

jca

slapper999 wrote: »

Paullimerick
The OP's hot water is heating so the pump must be pumping the hot water through the coil in the copper cylinder to heat the water.

youtube.com/watch?v=q7ncVld1Yyw

Not necessarily, the copper cylinder could be heating via thermo syphon if the boiler is low down in the system with a straight clean run to the cylinder.

Leilak

Hi guys, just a quick update here.... I got the rads going by taking some advice here, I put the heat onto constant and turned the thermostat up to max. still didn't work, so I shut the whole thing down completely for 24 hours and when I turned it back on the rads came on lol just trial and error I guess and saved myself around 150euros + by not calling the expert

Thanks for all your help and hope u all have nice weekend