PRV pump keep starting up

[wmc]

Hi - we have had our bungalow replumbed - mains pressure tank, all new pipes, radiators etc and the plumber has fitted a PRV pump as a safety feature to pump water out through the loft to outside if pressure gets too high I assume? This is going off intermittently, approx 12 times a day, no water in any of the black plastic indicator traps and no water is being pumped through the release pipework to the outside. It seems to coincide with the water circulating pump starting up, and the boiler is always running when it happens. but doesn't occur every time, and of course not when the plumber/electrican is here. Plumber says it's an electrical issue, electrician says it's plumbing. Any ideas?

 

[Rodders53]

Need pics of the install and pipeworks. Probably.
Details of boiler, unvented tank, and the pump makes and models also (for the manuals).

Is the boiler close by the HW tank?
Is it a pressure relief and boiler condensate pump??
If so when condensing boilers run they produce condensate by the litre. (Some say around 2 litres an hour when operating continuously).

The black 'tundish'(es) for pressure relief purposes would then remain dry, but the pump operates to get rid of the condensate as its' storage tank fills up.
But your plumber should have known that and told you to expect this cyclic operation of the pump.

Both the water and electrics side should be within the scope of any half decent plumber with the unvented and boiler install qualifications. It's not rocket science after all.

 

[wmc]

thank you - it's an oil fired non condensing boiler, approx 16m away. I've attached a photo of the general layout and a close up of the pump that keeps activating.

 

[ianmcd]

The pump should only activate when the temp and pressure releif valve operates, the pump has a sensor and when the water reaches a certain level the pump activates, as there is no water coming out the outlet when the pump operates then you have a faulty pump

 

[Rodders53]

High Temperature & Pressure Relief Pump

‘Granville’ The heavy duty giant! This High Temperature & Pressure Relief Pump is manufactured in the UK this heavy duty, high temperature tank pump incorporates thermal overload protection and high level alarm switch. Ideal unvented cylinder T&P discharge and steam humidifiers

www.pumph.co.uk

The float switch operates the pump with 100mm water or more in the tank, and stops when 95mm or less is left in its tank... That's not a very big level difference.
Can you see into the tank easily? to estimate how much water is in it? and also check the float switch movement?
Does the floor wobble or bounce in that area? Could the water level in it be changing enough for it to operate the float switch in that case?
Float switches are pretty basic devices with little to go wrong.

The 12 month warranty needs the whole unit returned and excludes any contribution to any labour costs to remove/refit.

So that means the installer will have to provide a replacement to you and send your faulty unit back.

The PRV pump box should have a 24/7 mains in feed (i.e. not switched by any heating or hw demand) and the second wire can be wired to an alarm or (probably better) to interrupt the mains feed to the boiler and controls so as to prevent the boiler or HW tank from letting by any more water than the tank can safely hold with a pump fault or outlet blockage. Ideally you'd want both cut out of the boiler and an alarm to sound.

Was there really no way of getting a waste pipe to the drains into this location and use gravity rather than a pump?