Monsoon pump question – Pump cycles periodically – Normal?

[robinsmith30]

Hi guys,

We have low water pressure in our flat, so there is an electric monsoon pump. When switched on, if we use a tap (or shower or toilet flush) then the pump kicks in to increase water pressure. If the pump is switched off at its isolation switch, the pressure is much lower.

The pump comes on for as long as a tap is running and switches off, but we do notice that when nothing is being used, the pump switches on for a very short time (5 seconds max). This happens throughout the day about 10 times an hour.

Is this expected behaviour, or does this perhaps indicate a leak. Why would the pump come on when nothing is being used.

I’m not sure if it is relevant, but we have a gas boiler and hot water tank. The only ‘devices’ we have are:
- Kitchen – 2 taps, and washing machine and dishwasher.
- Bathroom – 2 taps on sink, 2 taps for bath/shower, and toilet.

Any advice on whether this is normal (or not) would be appreciated.

Kind regards,

Robin

P.S. As at night, the noise of the pump is annoying we are thinking of replacing the isolation switch with a timer switch that is off between 23:00 and 06:00. This would stop the pump coming on during that time, but not sure if this is the right solution.

 

[Riley]

It's definitely not normal. I would be tempted to get onto Stuart Turner how old is the pump

 

[steadyon]

My first port of call would be the WC. If it uses a flush valve and this is leaking slightly (into the WC), this will result in a periodic slight refill, which might cause the pump to run.

 

[zgjebsi]

You have a leak, dripping tap or overflow pipe issue. You need to isolate and inspect those

 

[Riley]

The boys speak true. Sorry last one of these I looked at was a faulty pump. Certainly do the checks first. Toilet most likely culprit

 

[Dsp]

You have a pressure drop that the pump is seeing and pumping back to its set pressure the problem is finding the drop isolate all outlets if possible and see if it still happens if it does probably a leaking return valve in the pump if not it's an outlet toilet fill valve is normally the culprit as it won't show a slight leak into the cistern for a very long time

 

[gassafe]

Does the pump have a mini expansion tank on it? Might need repressurising

 

[Best]

Shouldn't really have a pump supplying the toilet cistern if possible.
If you take a look inside the toilet bowl, at the back of it with a torch, you might see a trickle of water running down. A wipe with a piece of toilet paper to dry the bowl will show if water is running.
Those modern push button toilets have a flush valve with a flat rubber washer seal, which lets water pass eventually

 

[robinsmith30]

I've done some invesigation
1) The pump is a (Stuart Turner) Monsoon N1.5 Bar Twin.
2) There is no evidence of a slow 'leak' into the bowl.
3) I've also looked for other signs of a leak but found none. It is a second floor flat, and leaks usually come visible to those below and this has not been the case.

I'll look to engage a professional plumber and look to source one with experience of such matters in the appropriate forum. The location is LONDON NORTH.

Thank you to all who responded to the forum and I'll report back with an update in due course.

Cheers,

Robin

 

[thompsonbrown]

Could just need the nrv-seals cleaned. Is it a negative head pump?

 

[robinsmith30]

I've spoken to Stuart Turner support and have been told that the unit Monsoon 1.5N bar twin is no longer available and out of guarantee and they have stated that the 'equivalent replacement' is the Monsoon Universal 2.0 bar Twin. For this model "Monsoon Universal pumps remove all the guess work from selecting a pump, being fully automatic they will function under both positive and negative head conditions"

However, they have advised that if properly fitted there should be an isolation value on each of the two pump outlets (outlets are indicated by yellow arrows). If these isolation valves are turned off, no draw will be placed on the pump, and it should not cycle. If it does still cycle then this indicates a fault in the pump/could be a result of pressure loss. If it does not cycle then there may be a leak somewhere downstream of the pump.

I will check whether I have isolation valves on the outlets and undertake the tests described.

Cheers,

Robin

 

[thompsonbrown]

I've spoken to Stuart Turner support and have been told that the unit Monsoon 1.5N bar twin is no longer available and out of guarantee and they have stated that the 'equivalent replacement' is the Monsoon Universal 2.0 bar Twin. For this model "Monsoon Universal pumps remove all the guess work from selecting a pump, being fully automatic they will function under both positive and negative head conditions"

However, they have advised that if properly fitted there should be an isolation value on each of the two pump outlets (outlets are indicated by yellow arrows). If these isolation valves are turned off, no draw will be placed on the pump, and it should not cycle. If it does still cycle then this indicates a fault in the pump/could be a result of pressure loss. If it does not cycle then there may be a leak somewhere downstream of the pump.

I will check whether I have isolation valves on the outlets and undertake the tests described.

Valves should be fitted on flex pipework attached to pump.

 

[robinsmith30]

Thank you ThompsonBrown, yes you are correct. The valves are not on the pump itself but on flex pipework attached to the pump. Thank you for the clarification.