Heating failure after radiator bleed

[chardir]

My heating system has stopped working completely after I bled a couple of radiators today. The symptoms are that the pump is very hot but the boiler is not firing up (not even attmpting to) and obviously all radiators are cold. I've checked the tank in the loft and it's full. Before bleeding the heating was working reasonably well but was quite noisy.

Please can anyone help?!

 

[tryitandsee]

Check the pump is spinning. Look at FAQ's at forum front page.

 

[gasandoilman]

what boiler is it ??

your tank in the loft may be for stored water not heating
have you a system boiler or combi?

 

[Soggy_weetabix]

Blocked cold feed?

David

 

[chardir]

Yes, the pump is spinning.

The boiler is a Potterton Netaheat. There are two tanks in the loft, the smaller one is definitely for the heating system. I've now found that the boiler does fire up for a minute or two when I switch on the CH from cold.

 

[chardir]

Blocked cold feed?

Sounds possible, how do I check it and unblock it?

 

[gasandoilman]

It is a blocked feed,you can use a good magnet it will stick where the block is.
It will be where your cold feed enters the heating system,usually in the airing cubbourd

 

[gasandoilman]

you can re fill from a drain off to get you out of trouble using a hose from an outside tap

but have someone in the loft to let you know if it over flowa using a mob phone

 

[bengasman]

lack of flow prevent heat taken out of boiler so the boiler stat is satisfied. probably sludge. search forum

 

[chardir]

If the cold feed is blocked how do I unblock it?

Not sure I understand how to re-fill, gasandoilman? Where would I attach a hose?

 

[Slugbabydotcom]

you can re fill from a drain off to get you out of trouble using a hose from an outside tap

but have someone in the loft to let you know if it over flowa using a mob phone

Refilling from a drain off may not work It is likely that the jumper will act as a non return valve and close, thus stopping water from getting into the system. Meanwhile the drain off cocks of old didn't have a packing gland so any water would pee out from around the threads. Also once water gets into the system, if the feed is blocked then water that you do manage to get in will only come out of the expansion pipe.

Instead make a proper connection for your hose onto the vent then let the water blast it through. If the blockage clears then the tank will fill up. Let it fill up and let it overflow. Man in loft is still required incase the OF pipe struggles to clear the water.

If its really solid then even this may not work so the only option you will have is to locate the blockage somewhere near where the feed pipe enters the system with a magnet. Plug the feed pipe drain the system down and then cut the offending section out.

As I type this I can see where gasandoilman was going. This is only a temporary measure that would get water into your system and allow it to work for a while. If it was Christmas day tomorrow then I would do it that way just to get you over Christmas. It ain't so best to do a proper job.

 

[bogdoc]

Did you turn off your heating before bleeding? If you didn't and the pump was running you may have sucked air into the system.