Will My Boiler Be Able To Cope?

[darbo1103]

I have a WORCESTER BOSCH GREENSTAR 34 CDI combi boiler, which is used for heating a domestic hot water. The boiler is over rated for our needs, but I thought if I'm buying one, it might as well be a big un! It pumps out plenty of hot water and heat through the rads.

I have a TRITON ENTICE 10.5 kw electric shower in the bathroom. The shower suffers from low pressure quite a lot and sometimes showering is a nightmare and takes forever. It's the third electric shower we've had over the past few years and each one has been used daily by four of us. I've even replaced the heater element as it blew a while back. Because of this, I'm looking at the option of changing it for a mixer shower or a power shower over bath instead.

My questions are, can my boiler run either of these showers? The boiler is located downstairs and the bathroom is upstairs. Would I need a pump of some kind bearing in mind that I do suffer from low pressure? Would it be feasible to do? Thanks in anticipation.

[The Builder]

A power shower is usually run from a gravity system (immersion cylinder plus roof tank.)
For a combi system, you would use a thermostatic mixer shower.

With the great benefit of hindsight ... I would have gone for a gravity system in your case. You have obviously, very poor mains pressure, plus four people in the house. Two common reasons for combis proving to be a right pain.

First off, I would ask your local water supplier to visit and take a look at your main. There could be an old, furred-up supply pipe. Maybe the main stopcock is half blocked up.

If the main is at the best level possible, and the running clear, then pressure can be boosted easily, but the pump and storage equipment needed can be quite expensive.

I wonder if the low pressure problem with your shower is more to do with others drawing off water in the rest of the house while you shower.

If other taps give a good flow and pressure from the boiler, then I would suspect the shower problem is down to the cold supply to it suffers from a very tortuous route, maybe with a lot of branching to other outlets. If your mains pressure proves to be Ok, then maybe a dedicated pipe run from the incoming supply directly to the shower may help.

Something, somewhere is way out of whack with your system, I suspect, Darbo, but I'd talk to the Water Company first.

[The Builder]

^^^ sorry about some of the twisted syntax up there, but I guess you know what I'm trying to say.

[darbo1103]

Thanks for your help and advice. I've had the local water authority in a while back as the low pressure problem has been a pain for quite some time (years!). They've done flow tests at the tap nearest to the mains inlet and furthest away and everything is as it should be pressure wise. The mains I draw water from also supplies, I think, three houses, including mine (the houses were build around 1936) and I suspect that the drop is pressure could also be down to my neighbour's using water as well.

Oh well, thanks again for the advice, I may get a local plumber in to see what, if anything, can be done to resolve it.