Water leaking from boiler & pump screeching - Help Pleas

[Tamrabam]

My problems started after I re-filled the heating system after draining down to fit TRV's to three radiators. I suspect the boiler expansion tank cold water feed line is blocked as I re-filled by using mains cold water via a hose to the boiler drain valve. The upstairs radiators do not bleed (due to lack of water?) and are only hot at the bottom and there is a water gurgling sound in the radiators. Last night I decided to "top up" the water from the mains and this seemed to work as I successfully bled all the radiators and they were piping hot. However, 20 minutes later I noticed water coming from under my Turco 70/90 oil boiler and the circulating pump started screeching after approx 15 litres of water had been mopped up. Is the boiler likely to be damaged or is there a pressure relief valve that is putting the water onto the floor? The pump impellers are turning and after using the bleed valve the pump seems to work for a while then it airlocks again. I have tried blowing the 15mm feed line in the feed tank but to no avail. Are their flexible rods available for 15mm pipe? Due to laminate flooring throughout house, I am unsure where pipes run! Should I drain the system down and try again? How do I know if the pump is really working properly (could the impellers be worn down?). Is the boiler knackered? The water tank side is a gravity system. Any ideas appreciated.

 

[Slugbabydotcom]

I suspect the boiler expansion tank cold water feed line is blocked

Me too from what you said.

What I would try with that is to run a temporary hose from the cold mains going into the tank; to the vent, and hope it blows the blockage clear up through the feed and back through the tank then out of the overflow.

In my experience this works sometimes. If you are not lucky then you need to find where the feed pipe tees into the system. This is where your blockage will be. The blockage can usually be detected with a magnet.

EDIT

However, 20 minutes later I noticed water coming from under my Turco 70/90 oil boiler and the circulating pump started screeching after approx 15 litres of water had been mopped up. Is the boiler likely to be damaged or is there a pressure relief valve that is putting the water onto the floor? The pump impellers are turning and after using the bleed valve the pump seems to work for a while then it airlocks again.

I'm a bit concerned as to where this water came from. If you do try the mains to vent idea get someone armed with a mop and a loud voice to keep an eye on the area in question or better still investigate it further before you start.

 

[Tamrabam]

Thanks for the advice Slugbabydotcom. I will have to buy more hosepipe to get fom my bathroom tap to the f&e tank in the loft.

The leak only occurs when the central heating is switched on and seems to get worse as the water gets hotter. It dries out when left overnight.

How do I use a magnet to detect where the blockage is, bearing in mind I can't easily get under my floorboards?

Does anyone know whether or not the Turco boiler has a pressure relief valve or not?

Regards

Tamrabam

 

[Tamrabam]

The leak only occurs when the central heating is switched on and seems to get worse as the water gets hotter. It dries out when left overnight.quote]

I can keep the central heating system "working" ok so long as I trickle feed cold water into the central heating system via the drain valve to replace the water lost by the leak! I think I will have to call in a plumber.

Could the burst be due to frozen pipes?