Twin impellor pump

[peter1958]

Morning, I have a good quality brass 3 bar twin impellor pump which has run my shower for 3 years.
My problem is the bathroom handbasin. I have a high pressure tap which I like and do not wish to change. Mains cold water feeds it for teeth cleaning etc and obviously is fine. However, my gravity hot water is on the slow side.
Can I connect the hot side of my pump to the hand basin tap, without causing problem to the pump? obviously this is just for the short periods of time that the hot tap is used. It would mean that the cold side of the pump would just run without water passing through it.
I assume there would be a pressure switch on both sides of the pump?

Thanks

Peter

 

[Winston]

Not entirley a expert on this but I dont think this can be done as its a twin impellor it requires for the hot and cold to be used. I think your best option would be a single impellor to be added to the gravity hot water.

 

[peter1958]

Thanks for reply,
I just thought that there must be some times when the shower is only using one side of the pump. Say having a cold shower, or hot if the hot supply is at user temperature.

 

[Winston]

No I dont believe this happens as you would be scolded or frozen I believe if you were to do this you would get pump cavitation introducing air into the system causing you problems.

But dont take my word as I am very new but I am sure one of the experts will be able to assist you further but good luck

Why dont you fix the pump so its for the whole house bar the toilets?

 

[peter1958]

I can do whole house, very easily, but it would still be hot to kitchen sink and handbasin. Cold is all mains. Don't like using stored water for cleaning teeth etc.

 

[Phil]

Winston is right it cannot be done, if my thinking is correct then when you turned on your hot basin tap it would turn on the pump and pump the hot water to the tap (which would be a fair force) and it would also try pumping cold to the shower valve.

The shower wont be on so it would pump against a dead head which the pump would not like (or the manufacurer who has to guarantee it!).

 

[Plumbstar Tom]

You need to check on the pump

Does it have separate reed switches? A hot nd a Cold

Is it a shower pump? as it may not be suitable for tap use

 

[secret squirrel]

Again, not too sure but you need a system pump? have a look on the salamander website, its very useful..

 

[peter1958]

Hi Phil
Yes it would be a fair force, but i need it for the tap it required 1 bar minimum.

With regard to shower, it again is a high presure digital shower 1 - 5 bar so it should be ok. If it were on mains combi boiler, it would be under pressure all the time.

The pump is a Grundfoss Watermill 3 bar, all brass etc

Peter

 

[Phil]

I was really talking about damage to the pump, not the shower.

 

[stevetheplumber]

Morning, I have a good quality brass 3 bar twin impellor pump which has run my shower for 3 years.
My problem is the bathroom handbasin. I have a high pressure tap which I like and do not wish to change. Mains cold water feeds it for teeth cleaning etc and obviously is fine. However, my gravity hot water is on the slow side.
Can I connect the hot side of my pump to the hand basin tap, without causing problem to the pump? obviously this is just for the short periods of time that the hot tap is used. It would mean that the cold side of the pump would just run without water passing through it.
I assume there would be a pressure switch on both sides of the pump?

Thanks

Peter

i think you can do this otherwise anyone with a pumped shower would not be able to take a cold shower double flow switches allow the pump to run if either switch is activated, if using one damaged the pump they would be wired in series to protect the pump running on one
ultimately the dfinative answer would come from the manufactuerers

 

[peter1958]

Absolutely correct, I telephoned Grundfos Watermill today and their tech guy said it would be no problem. Can even connect pump to all hot supply to improve other outlets.
Peter

 

[stevetheplumber]

Absolutely correct, I telephoned Grundfos Watermill today and their tech guy said it would be no problem. Can even connect pump to all hot supply to improve other outlets.
Peter

sometimes being right can get boring

 

[Plouasne]

sometimes being right can get boring

See your boiler rateing posting then, sorry Steve, I just could not resist it