Stuart Turner Monsoon Universal 4 bar twin - HUNTING

[tryitandsee]

NB. Also I believe if the water temperature gets above 65 deg. it plays havoc with these pumps. Cavitation and air bubbles or something...

The other half keeps leaving the emersion heater on (which is old and has no thermostat, emersion heater that is!), which turns the pumped loft taps into dangerous steam jets. God only knows what it is doing to the pump

 

[woodfordma]

Morning

I tried a couple of things last night. First was to close the hot outlet and flush the loos. Both worked fine.

I then shut the stopcock at the mains coming into the house and quite soon after the pump when hunting. Although not sure how that would work as the cold water tank and hot water storage tanks are able to coninue supplying the pump no?

I did not try anything else last night. For example the tissue paper in the loo to double check for overfilling cistern, but if it is def the hot outlet which causes pump to hunt and loos are connected to cold I would put the chances of the loos being the problem pretty low down now.

Could it really be non return valves on this pump as remember, this problem has been going before and after the replacement with a brand new pump so I'd have thought that would almost surely eliminate that one. How can that be tested anyway?

Thanks

 

[picasso]

By closing the mains you have eliminated the nrv,s, everything points to a leak on the hot supply pipework.

 

[woodfordma]

Thanks. So basically, Im b*ggerd as I cant identify a any leaks anywhere. How would a plumber go about locating the leak if there is nothing visible?

 

[picasso]

try and isolate any sections you cant see, then turn off each section in turn until you narrow the problem down to one section, then its simply a case of replumbing that bit (often easier said than done)

 

[woodfordma]

Okay. Thank you all. I think this is where this frustrating journey comes to to a very disappointing end and finally where I might have to shell out a fortune to fix the problem or just to live with it the way it is until the leak becomes visible.

Thanks again for all your help / suggestions and theories. Greatly appreciated.

 

[Agile]

A lot of what you have been saying worries me because its not all complete.

For example you said the loos flushed fine. That was not the test! The test was that they refilled from the still on cold water supply.

You "turned off the mains water". For that test to be most effective it should have included turning on the kitchen cold taps and leaving it on so that any hot leaking to the mains could be better identified.

You seem to have said that turning off the mains water prompted the pump to cycle ( thats whats its doing and not hunting ).

If that was the case then it seems that turning off the mains created a cause and effect although I am not satisfied thats necessarily the case. Hence my request for an enhanced test with the mains not only off but depressurised and LEFT depressurised during the test.

Tony

 

[woodfordma]

Hi Tony

I dont think turning off the mains caused the pump to go off. I will need to leave the mains off for a longer period tonight and I can leave the cold tap in the kitchen on. I will monitor how often the pump comes on but after last night it seems likely to continue the same way it always has done. i.e every 15mins to half hour or so.

The loos did refill. I turned isolated the hot outflow then flushed. The pump then came on for a while whilst the loo cisterns refilled (which could only have been from the cold (if the hot was shut)?

 

[Agile]

I am reasonably confident that you are doing most of these tests properly. Its just that sometimes your wording does not fully confirm this.

You are now at a crucial stage as most of the simple causes have been eliminated.

Its important now to be more scientific like documenting the on time and off times with each condition.

You say there is no leakage but the problem indicates there is!

Tony

 

[doitall]

One test you were supposed to do was turn the mains supply off overnight, and check the water level in the storage tank had dropped or not.

Obviously you can't use any water during the test.

 

[woodfordma]

Morning,

Another nail in the coffin.

I closed the stopcock at the mains coming into the house, left the cold water tap on in the kitchen (which trickled) and the pump went off approximately every 15 minutes for the hour and a half I tested it. This is pretty normal, although it seems to go off more often in the evening than during the day (for example when we are home at the weekend I dont hear it that often).

The cold water storage tank is not very accesible as we have boxed it in as it is in the bathroom therefore not really possible to check that.

One other thing is that if I solate the hot outflow and then open it again then the pump does no go off. Although If I solate it and leave it just a minute or two, when I open it the pump will go.

 

[doitall]

Why did you leave the kitchen tap open, interesting to note it trickled, any idea why.

Other than that if you can't do the tests, there's no point in trying to help.

 

[Agile]

He left the kitchen tap open because I asked him to.

That was because I did not want any valve leakage to be pressurising the pipe.

Just as well because either the valve IS leaking OR there is pumped hot leaking into the cold supply.

For plumbers and householders it is bad practice and asking for problems to mix pumped hot with mains cold in the same taps or showers.

Tony

 

[woodfordma]

Tony

On our first floor bathroom we have two basin mixer taps and a shower mixer. When I have the taps / shower on but all the way over to the cold side the pump does not come on and it is fed by mains. If I mix in some hot obviously the pump kicks in. This must mean that the pumped hot is mixed with mains cold?

Is this definitely the cause of the pump going off do you think? Why did it take a month or so for the pump to start hunting after the works were completed.

British gas hooked up the first floor cold to the mains and the hot from the pump because at this stage we did not have mixer taps. After the rennovation we installed mixer taps and shower as mentioned above and so the pumped hot and mains cold must be being mixed.

How do I confirm that this definitely is the problem? What would be the solution if it is. Change the mixer taps / shower for individual hot and cold? It would not be at all easy to plumb pumped cold down to the bathroom therefore the first option sounds the best. I'm just worried about where the pumped hot and mains cold get mixed at each point and especially whether for the tiled shower it will be possible to change the mixer tap without too much destruction.

Many thanks

Mark

 

[doitall]

If that were the case Tony the dribble would be warm. You would also get warm water from the mains.

I still say the problem is most likely connected to the new bathroom.