Hot water pump cycling


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Old 03-18-16, 03:21 AM
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Hot water pump cycling

I have a Monsoon 2bar pump for my hot water. It's the type with a pressure cylinder on top as I don't have a very high feed head.
It has worked fine for a couple of years but now I have a problem:
When I turn on a hot tap, it takes a couple of seconds before the pump kicks in & water comes out at high pressure. Also, the pump cycles (on for a couple of seconds) every few hours, even when no tap is being used.
If I pressurise the cylinder as per the instructions, plenty of water is pumped out of the open tap & the issue goes away for a few days, then returns.
The manufacturers suggest I shut off the outflow in line valve & see if that cures the cycling. It does. This suggests the issue is not the pump but in my plumbing system.
I have replaced a slightly weeping kitchen tap, but have no other water leaks as far as I can tell. They say it could be a fault in my shower mixer tap (I have two) but don't know what this means or how to check or fix.
Does anyone have any ideas please?
 
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Old 03-18-16, 04:34 AM
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With pressure on the system I would first depress the air shrader valve to remove all of the air then see if water comes out.
If it does and you have a bladder type pneumatic tank the bladder is bad which would require you to replace the tank..
 
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Old 03-18-16, 07:43 AM
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Regarding the shower mixing valve comment....I suspect what they were suggesting is that sometimes those valves can allow hot water to flow to the cold side (and vice versa) without water leaking out. Normally pressure on the hot and cold side is the same, so the cross flow doesn't happen, but with your pump, pressure may be higher on the hot side and allowing water to flow into the cold water line. You could test this by turning off the cold water valve to the shower (if there is one) which would prevent this from happening. If that fixes the problem, then you could try rebuilding the shower valve.
 
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Old 03-26-16, 04:17 AM
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I've depressed the valve & there's no water coming out. No air either as it seems to have no pressure at all.
 
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Old 03-26-16, 04:20 AM
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As it's only a 2 bar pump, I imagine the hot & cold water pressures are roughly the same so can't see why the higher side would be forcing water across.
 
 

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