Vent pipe discharges water all the time

[smn]

I had a boiler fitted 2 years ago, an Ideal Classic FF250, to my existing system.

There are 13 rads, the hot water tank and pump are in the loft, the boiler is in the kitchen.

Lately some of the rads have sludge and are cold.

Now I have noticed that when the boiler is on, the system works OK but the vent pipe continuously discharges into the expansion tank sometimes causing a small drip from the overflow. This may have been happening for a while.

Is this normal?

 

[ChrisR]

NO , not normal. The level when system is off should be very low in the tank.
Too high a level can mean loss and replacement with fresh oxygenated water, which leads to sludge.
Sludge can cause pumping-over which you describe.

Pumping over causes sludge.
Poor system design can lead to ingress of air which leads to sludge, or pumping-over.

Good boiler, unless you mistreat it, as any other! Worth getting someone to diagnose what the heck's going on.

 

[smn]

Thanks for the help

I did not have the problem before the new boiler was installed. Now I seem to have sludge.

I have a feeling the company I used were rubbish but I can't think how a new boiler alone would cause the problem

I think I should try flushing the system.

Thanks again

 

[breezer]

just a thought, perhaps in fitting new boiler they have dislodged sludge, or new pump more powerful?

 

[ChrisR]

Just emptying and refilling can introduce problems with sludge if it's there. It can for instance block the supply to all the downstairs rads.