Need A Wet Room

[ferlew]

MrF is really not coping with the en suite, so we have approached a local plumber.
He is suggesting rather than a separate shower unit, to run the new shower from the combi boiler. He says we will get better power. (Currently we almost have to run around to get wet!)
My fear is, would running it off the combi leave us open to getting scalded, if someone else turns on a tap, or uses the loo?
I didn't think to ask him this aft, now he has gone on his holidays.

[Zacs-Master]

Erm, no. They have a thermostatic mixer valve.

[tonyav]

Our shower is run from the combi boiler, ferlew. We have none of those problems.

[woofgang]

Mixer showers used to be like that but no longer. We have a power shower that takes water from the hot and cold tank storage and mixes it, its lovely

[ferlew]

Phew, thanks all, lad 2 is to blame for these worries, he said "Mum, if someone uses the loo, the cold will go off and you will get scalded"
I said, "the chap is a qualified plumber, surely he would not recommend something like that?"
Ta Tonyav and ZM, Woofgang....maybe that's what he was thinking of?

[woofgang]

yes ferlew, the first mixer shower we had 30 years ago was like that but not any more.

[ferlew]

Many thanks :)

[The Builder]

The only big problem that can crop up with Combi showers is where you have low mains pressure. Country areas and high ground are the worst.

With low(ish) pressure, it's not the scalding that's the worry, but the sudden drop in pressure. If a cold tap is turned on somewhere, it usually results in the shower being temporarily reduced to a dribble... not scalding though, because of the Thermostatic nature of the valve. Much the same when a hot tap is opened.

It all varies so much. Older houses may have smaller bore pipework bringing the mains in. Newer ones with a 25mm service pipe and a high pressure main tend not to have this problem.

[ferlew]

Thanks for that Builder, our place was built in 2002, we are however on the very edge of a village overlooking farmland.
When he comes back from his holiday, maybe I should ask the plumber to test the water pressure? Or would he do that anyway before proceeding?

[The Builder]

He probably wouldn't test the pressure automatically; only if he thinks there might be a problem.

I don't think you have anything to worry about. Such a relatively new house should not be a problem. If you find that when you open a cold tap, the flow reduces greatly when a WC is flushed, then it would be a simple procedure for him to test the mains pressure. He could then see if that ties up with the Combi boiler's specification.

[ferlew]

Thank you Builder.