CH Pump Problem

yartin · 2025-12-17T22:16:11+0000

I turned both valves clock wise and anti clock wise with no issue, does this confirm valves are in working order?

fixitflav · 2025-12-17T22:24:31+0000

yartin said:
I turned both valves clock wise and anti clock wise with no issue, does this confirm valves are in working order?

Do you mean the pump iso valves? From the pic they are multi-turn gate valves. If they go several turns both ways before meeting resistance they should be OK.

yartin · 2025-12-17T22:52:49+0000

fixitflav said:
Do you mean the pump iso valves? From the pic they are multi-turn gate valves. If they go several turns both ways before meeting resistance they should be OK.

Yes I did few turns clockwise until stopped then anti clockwise until stopped.

Johntheo5 · 2025-12-17T23:03:43+0000

yartin said:
Yes I did few turns clockwise until stopped then anti clockwise until stopped.

Suggest, opening & closing them several times, each time when shut give a little extra squeeze up which will help to get a effective seat/seal, when satisfied, remove (with boiler&pump isolated) that pump centre screw again, get a screwdriver or whatever and just push in the shaft a few mm, if no water, then you are good to go, take a snapshot of the pump wiring in its terminal box, remove the wires, remove the pump after carefully noting the direction of the arrow on its casing, clean up the flanges, install your new pump, wire it up, open the isolating valves and away you go.

Hadn't read post #45 so yes, try this first, have you established if the pump shaft is in fact turning??.

yartin · 2025-12-18T08:31:28+0000

fixitflav said:
It shouldn't be too difficult to remove the pump body to check the impeller etc, just 4 Allen bolts. No need to disturb the pipework. Close the pump valves first, or if you prefer, partially drain the system.
It would be a shame to replace the pump and find it's no better.

There is no other parts which can be faulty. The boiler fires only for 30 sec then stops for 30mins or so, the feed pipe from the boiler get very hot and return is cold, then the pump get very hot for no good reason. What else good it be, boiler?

Johntheo5 · 2025-12-18T10:19:52+0000

If your pump was working, shaft seen to be turning??, then remove the head, as suggested, post back with photos, if pump shaft wasn't/isn't rotating then go and get a new pump.

fixitflav · 2025-12-18T11:53:16+0000

yartin said:
There is no other parts which can be faulty.

Maybe, but it might be possible to fix the pump, eg by cleaning crud out of the impeller. And I still think it would be easier, and less likely to have complications, to remove the pump body to check. If it turns out the pump does need replacing you haven't lost anything. If the new pump is identical you could just change the body, to avoid disturbing the pipework.

yartin · 2025-12-18T12:55:14+0000

yartin said:
I haven't done anything since; few questions:
1. With hot water or central heating selected, would the pump turn if boiler not firing? IE: does the pump turn only when boiler is firing?
2. Can I test the operation of the pump without taking it apart? ie: by taking the middle silver screw and see if pump turning?
3. I have ticking noise nothing loud when boiler fires, there is no banging or nocking, is been there for a while even possibly years, the flame is blue and normal; does this suggest anything wrong with the boiler/heat exchanger? boiler is ideal classis cast iron exchanger
4. The issue is still the same, the boiler fires when HW or heat is selected only for 30 sec or so and stops, there are 2 water pipes on top of the boiler; assume feed and return, one gets very hot but other stays cold. The boiler fires back on after 30mins or so, in between the pump gets very hot. Why does the pump get very hot?

Thanks

There was a purpose for this post:
I booked a gas safe engineer yesterday morning; he said I need new boiler, new pump and power flush; total £3800 and spent time trying to convince me.

I asked him to test the pump but was ignored.

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CH Pump Problem

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