Baxi WM38/3RS No hot water or central heating

[senator2102]

Hi,
I drained down my central heating system which is approximately 12 years old to fit a towel rail and now my system is not functioning properly. It was ok before it was drained down.
The symptoms are the pilot flame is ok and the boiler does fire up every now and again and gets very hot but there is no central heating or hot water from the taps. Its as if the hot water is not leaving the boiler.There is a humming noise coming from the boiler or the large pump ??? type thing (that sits on top of the boiler) which I did not notice before. Also I cannot bleed the upstairs radiators as if no water is getting to them the downstairs radiators bleed ok.
Is there a simple solution to this problem.

Thanks,
Brian

 

[Dan Robinson]

Check that the pump is spinning (remove the silver screw with a rag unbderneath and spin rotor with screwdriver).

Otherwise you possibly have a blockage in the feed coming fromthe header tank.

 

[gas4you]

As you cannot bleed upstairs rads then it is most definitelt a blockage in your cold feed.

It will be blocked where the cold feed from the expansion tank 't's into the heating pipe work. It will need to be cut out and replaced.

 

[senator2102]

Thanks Guys for getting back so quick.

I have taken the large silver screw off the centre of the pump and can see it turning. The pipe on one side of the pump is very hot (input from the boiler I presume) and the other side although hot its not as hot and the further along that pipe you go it becomes cold which appears to me that though the pump is running its not pumping hot water. Can the system be air locked after me draining it down? Can you prime the pump it is a Grundfos UPS15-50 x 18? I can now bleed the upstairs radiators after about 2 hours they seem to have gravity fed over that period.

Thanks Again,
Brian

 

[Dan Robinson]

It sounds like the feed is clogged and there is not a full system load of water. Do as we've suggested and post back.

 

[senator2102]

Hi Dan,

Thanks for your help. I managed to sort it out by partially opening the pump input connector which allowed a lot of air to escape (a loud hiss being heard). I then partially opened the output connector and there was a small hiss and bubbles. Everything is working fine again. This was supposed to be a quick saturday morning job lol.
Many thanks for the help.
Cheers,
Brian

 

[Dan Robinson]

They always are...

Worse thing to say to a plumber is "while your here". Gauranteed that'll take longer than the original call!!!