Shower type recommendations

[jh]

Hope you can help me, I live in the top floor (3rd) of a flat roofed ex-council house, I have decent central heating and hot water with a standard potterton gas boiler. However, my shower is a basic 11kw electric shower supplied by mains cold water. For some reason in the winter the water pressure fluctuates a bit and the shower often complains of low pressure and switches off its element, hence a cold shower which is none too amusing when you are covered head to toe in suds!

The shower head is at a similar height to the the base of the hot water tank feeder tank if that make sense. I would like to run a shower from the hot water generated by the boiler instead of the electric one, but i have little experience in this area.

What are the groups recommendations and how much would various solutions cost?

Thanks

[The Natural Philosopher]

You need a pumped shower if the mains pressure is crap.

However its surprising to get massive short-term pressure fluctuations..does the cold tap flow rate vary?

If the actual mains flow rate is good and its just the shower that is crap, a Combi system might actually suit you. Heaven forfend I should actually recommend a combi..

in the end a cheap new boiler may not be much more expesnive than sorting out a pump.

And you could ditch all the tanks..scarpo value of copper is not insignificant..

[Jim Alexander]

You are implying there is not 11kWs worth of cold water at certain times in winter in which case an approx 28kW combi fed shower might disappoint, though the real problem is using a "basic" 11kW shower which may or may not even be working properly. Put in a better 9.5kW electric shower with decent temperature regulation that doesn't dump cold water when it cuts out, then think about a total DHW solution at boiler replacement time.

Jim A

[Andrew Gabriel]

Has it always done this? I'm wondering if it's some part of the shower which is deteriorating and would benefit from a clean or a simple replacement like-for-like shower, e.g. if it's scalled up. Have you got any other mains taps nearby and do they give a good flow?

Otherwise it will be a shower pump. I wouldn't entertain a combi if you're already low on mains pressure or flow rate.

[The Natural Philosopher]

Totally agree, but it seems odd that this pressure drop 'suddenly' happens.

That is usually symptomatic of a very localised problem indeed..in the shower, the flat itself or at worst the block of flats.

[jh]

The varying cold water pressure is a symptom of my block of flats as far as I know and only seems to happen between 7:45 and 9am each morning. However, when i use the cold tap at the same time there is no noticable difference in pressure, so im thinking it must be only a slight problem. I've told my managing agents and they said said yes some people with electric showers are having problems but didn't suggest that they were going to fix it.

Regarding the shower itself, it was fine for the first 10 months or so (fitted in March 2006), then the problem surfaced that following winter but we put up with it. Now I would rather get it fixed, than put up with it again.

As suggested I think the best solution so far would be to replace it with a 9.5kw shower and see how that goes. If it happens again very soon I probably should entertain other solutions.

[jh]

Thanks Jim, this sounds like a good option. Can you recommend any decent shower brands to look at?

[Andrew Gabriel]

If you are in a Thames Water area (London in particular), Thames issued a warning a year or two ago that they were going to reduce pressure in some areas to reduce loss by leaks. This was particularly aimed at anyone intending on installing a combi, who might find that it would no longer work. In many respects your shower is similar to a combi, in requiring a minimum flow and pressure to operate. In some blocks of flats, the pressure became insufficient to reach the top floors. There were legal cases brought against Thames who said it was the blocks' management responsibility to fix -- Thames only legal obligation was to supply water at a minimum of 1 bar.

See:

[Jim Alexander]

Haven't a recommendation as its years since I had an electric shower installed but Mira and Triton are commonly available. Look at Screwfix or the individual websites to get an idea what is available. Looks like you need to get a measure of available pressure and flow before you chose but some of the 9kW ish models are spec'd down to 0.7 bar.

Jim A

[Andy Champ]

John,

I don't suppose your shower has different heat settings? If it does, the cheapest solution might be to switch to the other one!

Andy

[jh]

Interesting point actually... It has two heat settings, one is full power and the other is half power (or 2/3rds power) and the problem happens on both settings. I think the low pressure cutoff detector has only one setting for both power modes. So maybe a less demanding shower would have a lower pressure setting. Well I hope so anyway!

[Adam Aglionby]

Had similar problem with top floor flat,low pressure in mornings when everyone has a shower....sodding thing was installed and tested in the afternoon.... Solution settled for was Triton pumped electric shower with its own header tank, hot water storage and header having been already ditched for under counter unit. Much smaller tank put in old hw header void soley for shower, thing sounds like a hoover but has been in rented flat for a few years now.

[A.Clews]

Thus spake jh ( [e-mail]) unto the assembled multitudes:

I'd definitely recommend a power shower (pumped type) to feed from your hot and cold water storage tanks. I had an Aqualisa Quartz installed early this year and I'm delighted with it, though it wasn't cheap (equipment plus plumber and electrician costs took it to not far short of a grand). Cheaper showers are of course available :-)

[Andy Champ]

I'd guess (guess, mind you, I'm not a plumber) that something is causing a transitory pressure drop that'd trip *any* shower. All you'll get will be one that doesn't squirt you with either (a) icy or (b) boiling water when it comes back on.

Pumped from storage is much better. That's what we have, to replace our old instant and there is no comparison.

Andy