Water pump for shower gets very hot

bobbybobbo

Hello

We just moved into a new property and the water system has a pump on the floor and a big water tank (immersion heater?).

Sometimes if my wife and I have long showers the water suddenly cuts out. I initially thought it was because of a small water tank and the hot water ran out. But no water runs at all. Shouldn't it at least run cold if the hot water runs out?

And the last time it happened I realised the pump wasn't activating when I turn the knob. Usually you can hear it kicking it into action when you turn on the taps. I checked the pump and felt that it was searing hot. Hot enough to burn me if I touched it for more than a second. Is this
normal? Should the pump be getting hot at all? Is it possible it's overheating and that's why its cutting out?

Thanks!

andyhop

Your running the pump dry

bobbybobbo

Thanks andyhop. Could you explain what you mean and how to prevent this?

EssexExile

He means your using water faster than the tank is refilling.

bobbybobbo

EssexExile wrote: »

He means your using water faster than the tank is refilling.

I see. But shouldn't I at least be able to run cold water? The tank is only for hot water right?

andyhop

The pump should be a twin ? Tank needs to be minimum 50 gallon

EssexExile

I don't know the details but you've got the hot tank & a cold tank in the loft. There's a flow switch in the pump, I don't know whether it's on the hot or cold side. Anyway, when the side with the flow switch runs dry the pump will stop. The pump will probably be ruined too is this happens often.

bobbybobbo

EssexExile wrote: »

There's a flow switch in the pump, I don't know whether it's on the hot or cold side. Anyway, when the side with the flow switch runs dry the pump will stop. The pump will probably be ruined too is this happens often.

So the answer is to just make sure to never use too much water? Alternatively is it possible to switch the flow switch to the other side once it runs dry?

bobbybobbo

So I just took a shower. A regular 7-8 minute shower, not very hot, luke warm water. And just me--usually when the water cuts out its after my wife and I shower one after the other.

After my shower I went to check the pump. It's still burning hot. I understood as per the above comments that it's only getting hot once the water in the tank runs dry. Surely it can't have run dry as the water never cut out and it wasn't a long shower. Should this pump still be getting so hot?

EssexExile

bobbybobbo wrote: »

Should this pump still be getting so hot?

I'll let you know after I've had a shower. It may be some time.

lstar337

bobbybobbo wrote: »

Should this pump still be getting so hot?

Possibly. Presumably it'll have hot water running through it, and generating heat itself through the motor in it.

Can you find a part number so you can look up its operating temperature?

I would think it is almost certain that the reason it all shuts off is because the tank runs dry. Basically you are pulling water out of the tank faster than the cold fill can put it back in. The system should have been designed to keep this scenario to a minimum, but there is no knowing what the conditions were of the people who had the house before.