Electric Shower Question

[allgonepetetong]

Chaps

When using the electric shower, should the washing machine fill, a toilet flush or basically any demand in the house for cold water the temperature on the electric shower shoots up until the extra demand stops and then it will return to it's previous temp..

Is this syptomatic of poor flow from the water main into my house?

I'm looking to replace the current combi with a mains pressure heat store system and think I need to replace the water main to the property.

Am I correct?

[Arthur Jackson]

Sounds like it. Unless you have stored water, mains FLOW is all important. More so than pressure really.

[Deva Link]

What's the flow like at the kitchen sink? I would say both flow and pressure in our house are tremedous, but we get the same effect, although the shower does try and adjust itself by winding up the flow rate. In summer though, with warmer mains water, it can go into overheat and drop the heater out so the shower goes cold.

It's bound to happen to some extent - a washing machine solenoid valve opening is like turning a tap full on instantly. Water will take the path of least resistance and that path is easier than flowing up to the shower, through its heater, along a narrow shower hose and out of the head. There might not be enough dynamic (flowing) pressure in the main to overcome this, even if the unrestricted flow was fine.

You can use a water accumulator to overcome short-term demands. But a useful size one would be quite big.

[Wings]

I own a block of 4 flats, where tenants over a period of time have occasionally complained about the water pressure when using the electric showers. Just give a thought of using a shower through a mixer tap, water pressure dropping at the wrong moment, “ouch” that can really burn parts you wouldn’t want burning.

[hairyben]

electric showers regulate temperature using flow, ie more flow over the fixed rated element= less temp and vice versa. You're never going to prevent this issue unless you have unusually great mains pressure and flow.

It is possible to install an electric shower using a boost pump on the low pressure (tank) cold if you have that- refer to manufacturers tech line as some will/wont permit this, for what difference it makes.

[allgonepetetong]

Thanks for your replies.

I'll take a look at the batch mixer tap tonight and see what happens when additional demand for cold water is placed abd report back.

thanks again