CH Pump Problem

[fixitflav]

Both ports valves are making the noises when turned on and off from the timer; suggests they are fine I thought. System is behaving the same when hot water or heating turned on; boiler fires then shuts off after 20 sec. The heating port valve is new Hanwell 1 year old. It would be odd for both die same time. What's best way to test them?

As the problem is the same on CH and HW, my money is on it being a pump problem. Similar thread https://www.diynot.com/diy/threads/boiler-kettling-periodically.651739/post-6136047 not long ago

 

[gas112]

, I unscrewed the whole of the red cup on the hot water AAV and nothing there, see photo attached, is this normal?

leave big screw off pump and turn everything on check if the internal screw is spinning freely its very rare the impellor actually comes off.
pump making an noise / boiler only staying on for 30 seconds no water out of highest point
Do you have a header tank in the loft supplying the boiler ?
Does boiler have a pressure gauge on it ?
it sounds like you do not have enough water in system possible blocked cold feed/ pressure down

 

[fixitflav]

its very rare the impellor actually comes off.

But the impeller can get clogged with crud, reducing the output. That's what happened with mine .

 

[yartin]

leave big screw off pump and turn everything on check if the internal screw is spinning freely its very rare the impellor actually comes off.
pump making an noise / boiler only staying on for 30 seconds no water out of highest point
Do you have a header tank in the loft supplying the boiler ?
Does boiler have a pressure gauge on it ?
it sounds like you do not have enough water in system possible blocked cold feed/ pressure down

Pump is quiet no noise at all when boiler is firing.
No gauge on boiler.
Header tank in the loft. Just checked it and it's full of water.


PS .
There were loud grinding noises from the pump one evening last week.
Then short grinding noises 3 days ago and been quiet since.

 

[gas112]

Header tank in the loft. Just checked it and it's full of water.


PS .

drain some water off and see if you can hear the header tank filling up if you cant you have a blocked cold feed

 

[yartin]

drain some water off and see if you can hear the header tank filling up if you cant you have a blocked cold feed

Where to drain water off from, header tank or of a rad?

 

[fixitflav]

Where to drain water off from, header tank ?

No, from the system, eg one of the drain points, usually near a rad. Ideally get somebody in the loft to check the level in the F/E tank falls as water is drained off. Better than just listening for it

 

[yartin]

No, from the system, eg one of the drain points, usually near a rad. Ideally get somebody in the loft to check the level in the F/E tank falls as water is drained off. Better than just listening for it

I can turn off the cold water which feeds the header tank first then drain from a rad drain point for few seconds, then lock the drain point and check if header tank level gone down, am I right?
If so then turn the water back on to fill tank.

 

[fixitflav]

I can turn off the cold water which feeds the header tank first then drain from a rad drain point for few seconds, then lock the drain point and check if header tank level gone down, am I right?
If so then turn the water back on to fill tank.

Yes, that's fine, and has the advantage you can tip the drained water back in the F/E tank, saves wasting any inhibitor.

 

[gas112]

do it for more than a few seconds but a minute /90 seconds should do it

 

[yartin]

do it for more than a few seconds but a minute /90 seconds should do it

Thanks I will do it on Saturday. Two observations, re photos attached:
1. The magnet is sticking to the copper pipes, does it mean anything?
2. There is a service valve open only half way from day one, does it matter?

 

[Exedon]

Magnet sticking to pipework = crud than needs to be removed.
The valve appears to be a bypass don't touch it will leak for fun.

 

[yartin]

Magnet sticking to pipework = crud than needs to be removed.
The valve appears to be a bypass don't touch it will leak for fun.

magnets sticking to more than one pipe, 15mm and 22m pipes, how to remove crud, manual flush?