DIY Doctor UK DIY Forums

I am about to rebuild the bathroom and want to install a power shower. The house currently has a conventional, gravity fed, heating system with two tanks and a DHW cylinder. This supports ten rads. Thinking about the cold feed I need to install for the power shower, it occurred to me that I could take the opportunity to replace the boiler and lose the tanks & cylinder by using a combi. This leaves some questions:

1. Is there a huge increase in pressure for the rads? Should it take the strain or will an old system (10 years) produce leaks at every opportunity?

2. Will there be enough flow of hot water for a shower without a booster pump? Given that this all started with a desire for a decent shower!

Grateful for any thoughts / feedback.

That really is a tough question to answer. Yes there is a great increase in pressure but most systems will cope fine. However, it all depends on the condition of your existing system. The biggest danger maybe is if any pipes are buried in concrete floors. Not only is a leak impossible to find or repair (you have to be totally re-plumbed), because of the chemical reaction with the concrete, they seem to be more prone to failing.

As for the shower, you cannot fit a booster pump to a high pressure system. There is nowhere for the extra water to come from for one thing. The quality of shower depends entirely on the flow and pressure rate of your incoming cold main. If it is good, it will be better than a pumped gravity shower.

Thanks Bob that's very useful. I think I'll stick with the old system simply to avoid the risk of leaks, and I'm sure a pumped gravity shower will be an improvement on the electric job we currently use!

Thanks again for taking the time to reply.

Oh, definitely better than an electric shower!