Any experts in power-shower fitting here?

whitegoods_engineer

Hi, I bought a new power shower with integrated pump in order to have a crack at fitting it myself.

The only thing that is causing me a problem is a sticker on the shower stating that this must not be connected to mains water.

The cold feed will be coming from the bath cold tap feed which comes direct from the mains. I can't think of any non-mains cold water source in the house.

My question would be what would happen if I connected the cold to the mains supply. What reason is there for having this stipulation?

Any replies appreciated.

Myser

The sticker could mean that you should not install it directly to the mains cold water supply to prevent contamination of the drinking water. You can get around this by installing a WRAS approved non-return valve inline.

Or it could mean that it needs to operate at a reduced pressure and mains water pressure is too high (unlikely). In this case, you can fit a pressure reducing valve inline.

What does the manual say about this? Have you tried to contact the manufacturer or asked the retailer where you bought it from?

P.S. I assume you bought an electric shower and not a power shower? A power shower will also require a hot feed as well and cannot be used with mains water pressure. This guide explains the difference:

http://www.creda-showers.co.uk/media/uploads/Creda Manual%

southcoastrgi

because they aren't designed to be connected to mains pressures, also they req equal pressure from the hot & cold, your hot i presume comes from a cylinder & is therefore tank fed, so your cold must be the same, if you connect it to the mains then it prob won't work & it will prob damage the shower

keystone

Myser wrote: »

The sticker could mean that you should not install it directly to the mains cold water supply to prevent contamination of the drinking water. You can get around this by installing a WRAS approved non-return valve inline.

Abject nonsense.

Or it could mean that it needs to operate at a reduced pressure and mains water pressure is too high (unlikely). In this case, you can fit a pressure reducing valve inline.

Getting closer. It means it needs supplies of hot and cold to be balanced at the same pressure. If you connect it to mains cold you will never get anything but a cold shower as it will constantly overwhelm the hot.

P.S. I assume you bought an electric shower and not a power shower? A power shower will also require a hot feed as well and cannot be used with mains water pressure.

An electric shower must be fed with cold at mains pressure. The OPs power shower sticker says don't connect to cold mains. How can it be an electric shower?

Cheers

Myser

Thanks for your corrections keystone - been a long day! Nice to see someone has time to disect other's posts

Owain_Moneysaver

You must NOT pump from the mains supply. The reason for this is that mains water is at pressure within the supply pipe; any leakholes and the water squirts out of the pipe into the ground.

If you pump from the mains supply you are sucking water out of the supply pipe. If the mains supply pressure goes low your pump will suck dirty groundwater through any leakholes and into the water supply.

If you have mains cold and tank hot, then you pump ONLY the tank hot to bring it up to a similar pressure to the cold, then feed the similar-pressure hot and cold into the shower mixer. Such a pump will be a single-impeller with one IN and one OUT connection. You probably need to buy a separate shower pump rather than have it combined with the shower unit. Advantages of a separate pump include not having mains electricity in the bathroom, and all hot taps in the house can be pumped, not just the shower. Not all single impeller pumps are intended to pump tank hot to be mixed with mains cold, so check the specifications carefully.

Pumps intended for tank cold and tank hot have two impellers (and this probably includes most power showers with integral pump).

A pumped shower will use more water so if your hot water cylinder is small you may find yourself running out of hot.

Owain_Moneysaver

keystone wrote: »

An electric shower must be fed with cold at mains pressure. The OPs power shower sticker says don't connect to cold mains. How can it be an electric shower?

You can get electric showers (heats the water electrically) which include a pump, so you can run an electric shower on a tank cold supply.

Stooby2

It sounds like you may have to run a cold supply from your cold water tank in the loft - assuming you have one and not a combi boiler.

Either that or take the shower back and get a different type.

keystone

Myser wrote: »

Thanks for your corrections keystone - been a long day!

Au plaisir. The point of the link is?

Nice to see someone has time to disect other's posts

What is that supposed to mean? It was rather late in the evening. Anyway if the information given is plain wrong then it needs rebuttal otherwise this place doesn't serve the OP particularly well. Oh and BTW I'm wrong on occasions too before I get a smart alec comment from the usual suspects and have no objection when I'm put right.

Cheers

keystone

Owain_Moneysaver wrote: »

You can get electric showers (heats the water electrically) which include a pump, so you can run an electric shower on a tank cold supply.

There are only a very very tiny number of electric showers which are gravity fed. IIRC there was an old Triton model that did that. Running the majority (99.9%+) of modern electric showers direct from a tank will result in a very poor showering performance.

The naming convention is:

Electric shower - cold mains fed only shower heats the water.

Power shower - electrically driven pumped shower that looks like an electric shower but requires balanced tank fed hot and cold feeds.

Cheers

southcoastrgi

Myser wrote: »

keystone

wow you have a profile page on this forum, who would have guessed

hold on I'll check mine southcoastrgi wow i do too