No heat to radiators after adding flushing fluid.

[Davrob6]

Be grateful for any tips. Noticed two radiators cold on bottom. Planned to remove and flush them out. Drained sytem today and put in some fluid to loosen the gunge as per instructions on the container. Did this ok. Refilled system. Turned heating on, needed a bit of bleeding but worked fine. Planned to leave for a week as per instructions and do the flushing then. Went out for two hours, turned heating back on. Boiler lights, pump working but no heat to radiators. Could it be an airlock. No air coming out of radiators so if it is it must be in the pipework.

Bungalow, open vented, 6 radiators. Cheers

Sorry I meant to ask how I can get rid of airlock or if it could be something else!

 

[yerino]

Sounds like an airlock.

Have you bled the pump (by unscrewing the little cap in the middle off till it dribbles out water).

Have you got any air peps in your airing cupboard?

 

[plumbplumb]

Vent the pump for starters.

On the face of the pump there is either a screw about the size of a 10p piece or it may be a black nut.

Turn pump off either at timer or by balancing speed selector between two speeds, remove screw or nut (if it is the nut type once unscrewed you may have to pull impellor shaft out a little) re-establish electric and see if it clears air. You should notice a difference in sound.

 

[Davrob6]

Thanks I'll try bleeding the pump tomorrow and let you know. Do I have to turn off the pump to bleed it?

What's an air pep? There are vertical pipes in the loft with bleed screws (about 6 to 8 inches long) one of which seems to be on the same route as the heating system. Bled those. Some air came out but no difference.

Cheers

 

[oph]

Do as the above have said a few times more. Seems as if theres air caught in horizontal pipework runs

 

[Davrob6]

Tried bleeding the pump but no joy. No sign of air or water. So decided to drain down again and refill very slowly by manually operating the valve to see how it went. Noticed the header tank wasn't emptying. Put my hand in and pulled away a lump of gunge from the outlet . It started emptying briefly but soon stopped again. Suspect gunge also in pipe. Could this be the problem and could it explain the airlock? Any ideas as to how I can clear the pipe?

I think I may need a plumber!

Thanks

 

[Dan Robinson]

Replace the pipe. Or depending on the boiler, seal the system and remove the tee joint where that pipe enters the heating system and replace with a straight section.

 

[Davrob6]

I have a plumber on the way. But for the sake of my education am I right in thinking this is what happened?

I drained the system, inserted the fluid and refilled.

This put air in the system in the form of tiny bubbles.

In this state the system worked for 4-5 hours because I turned it on once the filling stopped.

When I turned it off for 2 hours, the water level settled, the air rose to the top and there was no weight of water from the tank (because of the sod's law blockage) to push it out, hence the air lock and hence why it wouldn't bleed.

Just knowing helps!

Thanks for the advice all.

 

[zanwan]

I'm going to get shot down for telling you this but look for this mechanism in your boiler, if its got a black level, lift if for a few seconds, you'll hear it dump out a bit of water and air into the overflow pipe. If its a red/black knob, turn it a bit to release bit of air and water, then close.

This will clear the air lock and get your system running again.

As for running, i'm running from this topic because the boiler boys will be after me!

http://www.heating-parts.co.uk/product.asp?prd=205502

 

[David937]

Open vented system Naz, will probably not have a PRV.