Hot tank, cold mains, useless shower...

[PC Paul]

I have the common UK arrangement - cold from the mains, hot from a tank. The tank ( an unusual design I've not come across before with a cold header built directly onto the top of it...) is on the first floor, the bathroom is on the ground floor and offset about 20' from the tank.

The mixer shower is useless. But I like a powerful shower!

It's a rented place, so suggestions like 'get an oversized combi' are out, I'm stuck with the backboiler fed tank. The landlady is great and quite happy for me to fiddle as long as it all works reliably afterwards!

I've been told at the local shed to get an equalising valve (~£50?) to drop the mains to the tank pressure, then use a pump to raise it again... Seems daft. The shower comes off a mixer tap, so the pump will end up driving the bath filling too - not a bad thing, it takes ages..

I've also looked at the Grundfos booster pump - the UPA-15-90

$FILE/UPA%2015-90%2005%2003.pdf (I know, stupid URL!) and wondered if anybody had experience with these. I'm concerned that the lowish head on the hot tank (and cold header) would leave me suffering with cavitation and all that good stuff, even if I fitted the booster pump up by the tank.

Any thoughts? Other solutions? I'm trying not to spend *too* much as it's not my place, but £100 or so would be OK.

[john.stumbles]

a combination cylinder (not 'tank') commonly known as a Fortic (just as vacuum cleaners are Hoovers).

$FILE/UPA%2015-90%2005%2003.pdf> (I know, stupid URL!) and wondered if anybody had experience with these.

I've seen a Triton shower pump which connects between the mixer valve and the shower head. I don't know if they're still available but it sounds like the best (or least worst :-) thing in your situation. You could probably DIY something similar with the 'home booster' pump you've already looked at: just make sure it's buried away somewhere where water, electricity and human flesh can't meet.

[end user]

we had a similar situation in a friends flat i rented for a while, the hot water tank pressure to the shower was increased by fitting a pump and the cold water pressure(from the mains) was reduced by fitting a water pressure reducing valve, it took hundreds of mainly cold but sometimes scalding hot showers to eventually find someone who could figure out a soloution, we were almost calling out the ghostbusters

Hope this helps

[mike ring]

"PC Paul" wrote in news: [e-mail]:

and wondered if anybody had experience with these.

I use one of these to boost my taps, not my shower (Triton internally pumped - it solves the flow, but not the heat, in winter 10.5 Kw is stil hardly enough)

But I'm not convinced it would give you enough flow for a shower, but I'm open to correction on that - if it would I think it would be a good fix.

What I worry about is your tank; you are right to be concerned about the low head of the header above the hot tank. But how is it connected?

If it's a short length of bloody good pipe I should think you'd be in with a chance; I've got about 2m head above the cylinder and a nice unobstructed

22mm pipe between.

It's all about getting the flow into the hot water tank - I've never seen your type up close, so I don't know. Also if your mains is a bit slow up there you might have to worry about not having enough in reserve, if you have a good mains flow into the headr you should br OK.

HTH a bit

mike

[PC Paul]

Hmm. Had another look at this strange tank now... it's a 'normal' size tank from the outsidt once I look closer and under the floppy jacket, it's actually two half size foam insulated tanks, cold on top of hot. The pipes linking the base of the cold to the base of the hot, and the top of the hot overflow to above the cold, are inside the foam too.

Having seen that, it means that the hot tank is obviously not that big, so maybe a pumped shower is too much anyway, I'd run out of water! :-(

So, plan B:

Since there is plenty of cold (mains) and a small amount of very hot hot, maybe I could use a thermostatic mixer shower/unrestricted bath filler in place of the cheapo plain mixer tap/shower that's there now. Screwfix have a couple at £160 up..

Anybody tried this sort of thing with a big pressure difference? Is it likely to be successful?