3 electric showers

Hi All

Stuck this on the plumbing website as I thought there would be an answer. My system runs cold for all outlets from the tank, including 2 electric showers via a Salamander pump. This means if you are having a shower or using one of the other cold outlets there is no loss of pressure. The Combi feeds the hot in the kitchen, two bathrooms and cloakroom. System has been working great.

Spanner, we have now had a loft conversion which means an extra bathroom. I know you can not run 3 electric showers of a household 100amp mains. If I use a thermostatic shower the pressure from the hot is not going to be there, I have run a simulation with just 1 hot feed on.

This can not be an uncommon problem, so what is the answer, priority board / get a three phase supply. The latter is going to be expensive.

Thanks

Magrah said:

so what is the answer,

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Stored hot water in a cylinder, either unvented if the cold supply is suitable, or pumped if not.
Heated via your combi boiler.

Magrah said:

. I know you can not run 3 electric showers

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Certainly not, and even two of them is likely to be overloading the supply.

Sorry how does that work. Surely you'd need zone valves and predict when you want a shower?

Thanks

We have two showers that work off the combi boiler but don't use them simultaneously. I've recently seen a free standing Haier Heat Pump that is quite low power https://www.linkedin.com/in/graham-hendra-a0b0426/recent-activity/all/ have no idea how effective it is but that could feed your new bathroom?

I have two instant electric showers on a 60 amp supply. DNO fuse has not blown while I have been in the house (5 years) and I note the inverter takes some of the load now, most times they are used.

I don't think this is ideal, and in parent's house will had a power shower, which got around the low water pressure problem, and my last house direct from the gas boiler, (not combi, a Main 7 well before Combi's came out) but the cost to change does not seem to be worth it.

I suppose the easy way out is two showers from the same overload, so if used together it trips. I have two showers as a garage converted into a flat with no internal access between the two, but we have the shower downstairs in the main house, so have to go down/upstairs each time we shower, not ideal, but not worth the money to change it.

So why do you want three showers? Will you want to use all at the same time?

Magrah said:

Sorry how does that work. Surely you'd need zone valves and predict when you want a shower?

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You need 2 zone valves, one for the heating and one for the new hot water cylinder. An entirely standard arrangement used in millions of homes everywhere.

As for using - you turn the mixer shower on and hot water comes out of it.

The cylinder is heated when it's needed by the thermostat attached to it switching the boiler on and off. No predictions required.
The days of people turning on some antiquated hot water heater two hours before a bath was desired went away over half a century ago.

Do you have low mains pressure? If not the simplest solution would be just to plumb hot and cold from the combi for your new shower - 24kw+ will give a decent shower (much better than your electric ones) and while the pressure will drop slightly when someones washing their hands, it won't be for long, assuming the dishwasher/washing machines aren't plumbed into the hot supply.