Change loft tank for unvented cylinder

fezster

grumbler said:

Bendy_House said:

robatwork said:

What exactly is your pressure and flow rate in l/min?

We have a massive Megaflo but the incoming pressure is about 1.5 bar and by the time that's gone to the loft where the cylinder is, it's probably about 1 bar. It's really not enough to get a really good shower and the pressure at the taps is adequate but not great. 

Sounds like the wrong choice for your circumstances, then.

Is there any way you can improve the incoming? Eg by a new supply pipe?

A new pipe can increase the flow rate, but cannot increase the pressure.

It can't increase static pressure but it certainly can maintain (net increase) dynamic pressure and flow rates. 

goodwithsaving

Thank you all for your suggestions and thoughts. I'm very grateful for all thoughts, opinions and bits of experience. The mains pressure is great in the kitchen, it's just the bathroom that is the problem. A thermostatic mixer is what I'd prefer most (I really am not fond of electric showers. I don't know why - maybe just what I grew up with and associate with a rubbish shower).
I am reluctant to spend a considerable amount when, wasteful as it may be, the end goal is to swap to a combi. 

I'm going to take all of your suggestions and have a word with the plumber about which is the best one to go down for now....

Thank you all very much indeed!

Section62

goodwithsaving said:

I'm going to take all of your suggestions and have a word with the plumber about which is the best one to go down for now....

I'd suggest not being over reliant on the opinion of a plumber who has already proposed an expensive solution to what should be possible to solve for far less money.

Spending a minimum of £1000 on an unvented cylinder (rough as that estimate was) was never going to compete in the MSE game when the alternative of a pump starts at a touch over £100 and needs less labour to install.  (not recommending this one, just confirming the ball-park cost)  https://www.screwfix.com/p/salamander-pumps-ct50-xtra-regenerative-twin-shower-pump-1-5bar/20423

That's assuming the problem isn't something more basic such as pipes being clogged, or a service valve which has been turned off and not back on properly.

Also see this thread for someone who was in a vaguely similar position to you who was having what effectively amount to salespeople trying to sell their preferred solution (and pooh-poohing the alternatives) rather than first doing the basic job of a professional plumber and diagnosing the problem.  https://forums.moneysavingexpert.com/discussion/6287422/can-should-i-switch-hot-water-systems/p1


If you've ruled out an electric shower (sensible decision IMV) and you ultimately want a thermostatic mixer, then assuming the pipework is all Ok and the head cannot be improved, the only realistic options remaining are a shower pump, or changing to an unvented system.  One of those should have one less digit on the final bill...   a decent plumber should know that.

In your position I'd probably ask a second plumber to quote for installing a shower plus separate pump so you have a baseline quote if the first one now comes back and tries to convince you a pump is the wrong solution and you need to go with his unvented option.

Bendy_House

You don't like electric showers, and you are not sure why, GWS? It's because you are normal.

I'd second Section's caution about relying on this plumber as it seems as though he hasn't explored options with you.

Can you confirm what kind of shower setup you currently have? Do I understand it correctly that it's a push-on shower hose on your bath mixer tap? And just how poor is the shower - would it be ok if the flow were, for example, doubled? Or do you definitely want more than this?

And, once a solution is found - a shower pump/unvented cylinder/combi/etc boiler is fitted - will you be upgrading the shower controls then to a proper thermostatic type (highly recommended)?

Perhaps time for a fresh pair of eyes on this job.

Are you able to go up in to the loft yourself and have a gander? If so, could you take a photo of the CWS (the largest tank) showing clearly where it's located, and ideally whether there's room above it where it could be raised? (Wishful thinking, but worth discounting!).

Alternative simple solutions to adding a conventional shower pump - this has a pump built in, and also provides thermostatic (steady) temp control: https://www.screwfix.com/p/mira-go-rear-fed-white-chrome-thermostatic-power-shower/27958