Expansion tank overspill - HELP!

[BenH]

JohnD

Right, where to start? Photos can be provided tomorrow, but until then:

The actual bend is about a foot above the current, reduced water level, curving up over the edge of the tank and then back down again along the side of the tank.

The whole gubbins is in the loft about 2m above the pump and the same distance away on the flat, but the two feed pipes join the rest of them just above the pump in the airing cupboard on the 2nd floor landing, right next to the hot water cylinder.

Flow/suction - I have no idea which side they are...maybe the photo will confirm one way ot t'other.

The previous plumber used a non-power chemical to clean the system when he put in an new radiator late last year, but there is no sediment in the bottom of the tank, only a rusty tinge to the plastic. The water in the F&E tank is otherwise completely clear.

Photos will follow, many thanks for the offer of a full diagnosis.

BenH

 

[JohnD]

the "bend" in the vent pipe needs to be higher. 450mm above the top of the F&E tank is considered the minimum, but as you already have a problem, I don't think it would hurt to have it 600mm or more.

Unless you are fond of bending pipes the easiest way would probably be to cut the existing pipe where it rises up, and insert an additional length. If you cut the pipe at a point above the level of water in the F&E (and the boiler is turned off) then water will not come out of the cut.

Compression (brass) connectors are easy to use with a couple of big spanners.


p.s. the link 62945835 posted earlier is very good. Have another look at the pic.

 

[BenH]

Yes, that diagram more or less describes exactly what I have, without the higher loop of the vent pipe before it dips under the lid of the F&E tank.

One other thing - my vent pipe drops into the tank the same side as the other feeds. That is to say, they are all on the same side of the tank, not on opposite ends like most of the diagrams show it. Only my overflow pipe connect the other side of the tank.

Photos to follow just in case.

BenH

 

[BenH]

UPDATE:

Just in case anyone's interested....

I did take pics, but have now solved the problem after taking advice from people here and then making one further adjustment; twas the room thermostat.

Basically, it's been lying about its temperature, and reads several degrees below its actual temperature. Turning it down to an indicated 18 degrees made no marked difference to the house temperature, but it did reduce the spluttering up above. The system does still cough a bit, but only after an hour or two, and only once or twice while the heating is on, instead of immediately, and every ten minutes thereafter like it did before. The F&E water tank level remains at ball-valve level, just above the feed, the vent pipe bend has been adjusted to well above the tank level, and all I need to now set mind at ease is a new tank with a lid that fits properly (just to do everything properly).

The only downside is that I now have to replace the living room radiator, as with the new lower temp setting on the stat, the radiator doesn't have a sufficient BTU rating to fully heat that room.

Thanks again for everything

BenH