Can you Install a Combination Boiler if There is a Pump Action Power Shower? Help and information on all topics relating to your central heating, air conditioning and ventilation issues.

[Nodiyidea]

Hi, I'm looking for a bit of advice. I had a new boiler fitted 10 months ago. It was done through the a contractor working under the Health Through Warmth scheme. The system I had was a heat only system with an immersion heater for hot water. When they initially assessed my property they told me they would be fitting a like for like system ie heat only.
However on the day of installation they fitted a combination boiler without telling me what they were doing. I only realised what was happening when I saw one of the workmen carrying the hot water cylinder out of the house. I spoke with the lead engineer who assured me all was fine and this would be better for me.
A couple of months ago I was running hot water in the kitchen when suddenly all my electrics blew. My son who was upstairs shouted that there was water pouring out of the control panel of the shower. I turned the power to the shower off which fixed the electrics and had to turn the water off at the mains.
I called a plumber who told me the problem was that my shower was a pump action power shower and that the pressure from the mains caused by having a combination boiler had ruptured the valves in my shower and the water had then fried the electrics.
The problem I have is that the company that fitted the boiler are saying it's nothing to do with them. So I need to put in a complaint. Not being an expert I need a bit of help in phrasing the complaint in a way that makes it clear what they did wrong.
Please any help would be greatly appreciated. Thanks

[ericmark]

The company who fitted the central heating have likely broken the law, and clearly they must fix it.

The problem is if there is a pump which pumps from the mains supply it can under fault conditions cause negative pressure in the supply so if there is any leak it could suck ground water into the water main, and so doing contaminate all the mains water.

So as far as I am aware it is against the law, not just not recommended.

The same was done in this house, and they had to return and remove the power shower and fit a thermostatic mixer valve instead. I was forced to pay for the bits, but the company did all the work of fitting the new shower free of further charge.

I think it is controlled by Ofwat government department I think "The Water Supply (Water Fittings) Regulations 1999" I am not a plumber, I am an electrician, I think there may be a 12 litre per minute limit.

We found in real terms all we needed to do was turn off electrics to shower, it would work OK with no power going to it, which was why I had to buy new shower, but they fitted it.

[Nodiyidea]

Thanks ericmark. The company have no been out to inspect the damage and agreed that they were at fault. They have agreed to install a complete new shower and that it will be a thermostatic shower. The original shower isn't functioning as the the burst pipes leaked water into the unit which fused. We were lucky that the damage wasn't worse. And I think you're right that they broke the law, they didn't want to discuss that aspect at all.

[ericmark]

It seems then sorted, do say how you get on, it may help others.

[Browndoff]

I'd like to add just a general point to re-assure others who may have a Power-Shower AND a Combi-Boiler.
It's NOT inherently dangerous NOR against the necessary plumbing regulations - it depends on HOW the Shower is connected to the water-supply.
My house has an older-type OPEN heating-system [maybe different from yours?] but here the heating-system heats the radiators and the hot-water cylinder and it's fed by gravity from a cold-water storage tank in the attic [NOT directly from the cold-water mains].
Likewise, the Power-Shower is gravity-fed directly from another cold-water tank [also feeding the hot and cold water upstairs]. So any pressure-variation it can cause has NO EFFECT on the other systems and, unless it was itself faulty, would NEVER blow its internal valves or leak onto its electrics. This system has worked safely for nearly 30 years.