new flat - strange plumbing problems

[Joe Woods]

Hi,

I've just moved into a new flat and the plubing seems to have a mind of it's own. I can't even understand what the problem is. Here are the symptons:

- hot water in kitchen is extremely low pressure - cold water is fine

- hot water in WC, bathroom sink, bathroom shower all extremely high pressure, they seem to be connected to a pump, however the hot water flow spontaneously stops. For example, if you shower for 10 mins it will be fine, then the hot water will just totally stop. Then 1 minute later it will start again, but stop after 5 seconds, then stop-start constantly. It's as if there's not enough water getting into the tank or pump.

Can anyone point me in the right direction as to what the problem is?

Thanks!

JOE WOODS

[IMM]

Do you have a cold and cylinder? Combi? What does the pump supply? Shower only? all taps?

It sounds as it the pump is exhausting the cylinder of hot water and it is not being replenished quick enough. More info required.

[Christian McArdle]

Assuming you mean the water flow stops, not that it goes cold, I would strongly presume that:

1. You have a gravity fed hot water system using a cylinder and a cold water tank in the loft.
2. The bathroom is pumped, but the kitchen bypasses the pump, so has inadequete pressure/flow
3. The pump is so efficient at blasting you in the shower, the cold water tank empties and the pump stops.

Assuming this is the case, you'll need to ensure the kitchen is put onto the pumped system (could also be another problem, like pipe blockage). You'll also need to sort out the cold water tank situation. Possible solutions (either individually or in combination) assuming to wish to basically keep the same type of water system:

(a) Bigger/additional cold water tank. (b) Ensure all valves to refill valve are fully open, including stopcock. (c) Replace refill valve with wider bore type. (d) Remove flow reducers from refill valve. (e) Install multiple refill valves to increase flow. (f) Replace rising main to refill valve with wider bore (g) Fit a flow reducer on the shower, so the refill valve can keep up with the flow. (h) Move cold water in bathroom from gravity to mains, to allow all stored water to be used for hot only. (May require different type of pump if currently twin impellor).

Christian.

[John Rumm]

Yup that was the way I read it as well.

Remeber that you would still need a tap connected to the rising main for for drinking and cooking water though...

Probably the first one to try, many old ball valves give a feeble dribble of water into the tank. A friend had a similar problem, if you ran a bath you could hear the tank refilling for the next 40 mins! We replaced the existing inlet valve with a modern high flow one, and it can now refill almost as fast as you can run the bath.

Sounds like the current mains flow rate might be pretty poor. It would be worth measuring the flowrate (with bucket and stopwatch) at the kitchen tap.

[P.R.Brady]

OR:-

the pump wiring is screwed up and it's connected via (say) a thermostat or in parallel with the gas solenoid?

plus

some flow restriction in the kitchen.

Phil