Another pumping over question :)

Hi,

First post but often read the helpful info here.

Thought I'd run something past the forum..

A little history:
Over the last year or so been getting kettling from the boiler, started with cleaner/silencer etc, keeps coming back after a while.
Got a plumber in who just changed the pump and balanced the radiators.
Recently we lost the hot water, which turned out to be the 3 port valve stuck, which I replaced, and because I drained the system I noticed the header was quite mucky, dark brown with bits of black sludge.
I've filled it up with cleaner again but now want to find out what is causing it and if I'm going to need to get a power flush?

Now I've learnt, from reading here I may add, that it looks as if the system is pumping over, also learnt that the plumber probably shouldn't of set the pump to 3 on a small 3 bed house

I set the pump to 2 and the vent pipe was still getting hot, now another thing I read here is the height of the vent, it looks as if the vent has droped off it's clips into the header tank the end was submerged, would this be a cause for the over pumping? I had no idea that it had fallen off as I didn't know where it should be in the first place

So......I'm going to leave the pump on 2 and see what happens, but I'm wondering if the vent being in the header is causing damage to the system hence the noise etc?

Thanks.

I would have to say plumbing is incorrect. A properly fitted system does not result in pumpover.

Pump setting has little to do with property size. What if the plumbing is 8mm microbore, long lines from manifold to rads. Pump will indeed have to be set to a speed that delivers adequate amount of water. Speed may even have to be 3.

DP said:

I would have to say plumbing is incorrect. A properly fitted system does not result in pumpover.

Pump setting has little to do with property size. What if the plumbing is 8mm microbore, long lines from manifold to rads. Pump will indeed have to be set to a speed that delivers adequate amount of water. Speed may even have to be 3.

Click to expand...

Thanks for the reply, I have to say it doesn't seem to be pumping over (I could be using the wrong term, all I know it that there was hot water in the header tank) now I've moved the vent pipe back up to its original position, will be up and down the loft ladder tonight

Rads seem to be heating up fine on 2, I'm pretty sure the system hasn't been changed since the house was built, approx 15 years old

Hi

What type of pump as been fitted? Name and number please.

tincup said:

Hi

What type of pump as been fitted? Name and number please.

Click to expand...

It's a Grundfos 15/50.

Been keeping an eye on the header tank all evening still cold no sign of pumping over.

I am getting bubbling/banging/kettling when the boiler switches off, but been getting that for some time, before the new pump was fitted, and the reason the new pump was fitted.

new pump won't stop kettling.

Gwynn said:

tincup said:

Hi

What type of pump as been fitted? Name and number please.

Click to expand...

It's a Grundfos 15/50.

Been keeping an eye on the header tank all evening still cold no sign of pumping over.

I am getting bubbling/banging/kettling when the boiler switches off, but been getting that for some time, before the new pump was fitted, and the reason the new pump was fitted.

Click to expand...

The make and model of the boiler would be helpful.
It sounds like either the boiler stat or pump over-run stat may be faulty. A faulty boiler stat would cause hot water to be dumped into the expansion tank, this could also cause the open vent pipe to become detached from it's clips and drop into the expansion tank.

seco services said:

new pump won't stop kettling.

Click to expand...

I have to admit the old pump didn't look too bad, but I don't really know what I'm looking at

mlcinfl said:

The make and model of the boiler would be helpful.
It sounds like either the boiler stat or pump over-run stat may be faulty. A faulty boiler stat would cause hot water to be dumped into the expansion tank, this could also cause the open vent pipe to become detached from it's clips and drop into the expansion tank.

Click to expand...

It is a Gloworm Economy Plus.

The Boiler was set to max I've turned it down halfway, I think the boiler is cutting out when it gets hot, i.e. if you have the room stat up too high the boiler does stop and start.

I not sure about the pump over-run stat, how long should the pump run after the boiler turns off?

Also I have to add I originally thought the noise was just down to hard water furring, the reason for the pump over question (which I think has pretty much stopped as far as I can tell since putting the vent back up on its clips) was I read that this can corrode a system quicker? but the more you read the more possible causes you find, might as well rule as many out as I can

A little more info I've been checkng the pump over run.

When the boiler turns off by itself i.e. the room stat is set to max, the pump continues to run when the boiler is off.

When I turn the stat down to shut it off I get varied results, sometime the pump runs on, sometimes it stops, sometimes it stops then starts again for a short while, it is the later senario that seems to be the most noisy

Also getting air out of the automatic bleed valve when the banging happens but I guess that is the air that the boiler creates when it kettles?