HELP, stored hot water, cold mains

[rolleya]

Any advice much appreciated. My bathroom, currently being completely renovated is on the ground floor beyond the kitchen (very old house). I have a gravity fed system, hot water comes from loft at good pressure but the kitchen and bathroom are cold mains fed only . Is there a shower I can use (other than a mains only electric, and without having to change the cold feed so that it comes from the loft too?). Can I use a mixer such a Mira Excel? By the way, Trevi Boost has been mentioned to me and is not suitable as my pressures are too high. Many thanks for any advice, my (general) builder is getting near to the point where he will need to install the shower, but doesn\\\'t know what to recommend. Many thanks in advance. Anne

 

[Bahco]

You cannot use a mixer if the supplies are unbalanced
You will have to cold feed the mixer from the cistern ensuring the cold feed is sited lower than the hot feed to the cylinder to prevent scalding in the event of the cistern running dry, (unless you purchase a thermostatic shower).
Fit an electric one for ease.

 

[ChrisR]

You can use a pressure equalising valve to make the mains the same pressure as the gravity HW, then use a normal mixer. The 2 floors head will give you a reasonably good shower.

 

[rolleya]

thanks so much for your responses, very helpful and confirming what I found out last night from someone who fitted this exactly to their system and also from Bristan. Strange that Mira didn't suggest that but I guess they don't want the responsibility.
again tks a lot.

 

[granth]

Hi,

I have a similar problem but my hot water is from my combi bolier and mains feed but my cold water is gravity fed from a tank in the loft. I live in a ground floor masionette and access to the loft is through the upstairs flat.

The shower is a new shower but when turned on the flow is very bad and then takes about 2 mins to get to a reasonable level.

Could I also fit a pressure equalising valve?

Thanks

 

[Softus]

Hi granth

Sorry to be picky but this sounds like a candidate for a new posting.

S.

 

[rolleya]

not that it has anything to do with the above anymore, to go back to my original question and for the sake anyone looking for experienced advice, I had a Mira Excel shower (not pressure) fitted in the end, and a pressure equalizing valve installed on the cold feed as it was given to me by someone at work, but the shower has worked really well for a year now without the pressure valve ever adjusted at all, so that was probably not necessary. I haven't dared touch it in any case. The cold and hot pressures are noticeably different at the basin, bath and kitchen sink, but that doesn't seem to bother the shower system and basically it's worked brilliantly with an incredible amount of pressure considering the set up. Even with the drain of a dishwasher and washing machine, all of which are within 15 feet of each other at most, I couldn't have hoped for a better result. Once the shower was behaving erratically, water temp and pressure all over the place but I found out the head was badly clogged by limescale and once cleaned it was back to normal. Rgds, Anne.

 

[ChrisR]

This is useful feedback, thanks.

Your thinking's awry here though:
"put a pressure equalizing valve installed on the cold feed as it was given to me by someone at work, but the shower has worked really well for a year now without the pressure valve ever adjusted at all, so that was probably not necessary."

The point of an Equalizing valve, as apposed to a Pressure Reducing valve is that it will Equalize the two pressures. So they are very important valves, but do not need adjusting. They do need dismantling for cleaning out/greasing sometimes. Offhand I can't remember what there is to adjust - range, possibly. Therefore an Equalizing valve has to have BOTH H & C going into it.
If what you actually have is a PR valve and NOT an E valve, you've just been lucky that the mixer can cope.

E or PR valves don't work so well when you try to get the mains to match a 1 metre head gravity supply!