Which pump?

[armitageshanks]

Hi,

Can someone help?

I have installed a mixer shower in my bathroom assuming the cold tank in the loft above the bathroom and the hot tank in the bedroom next to the bathroom would all be in the right places to provide a decent shower. How wrong was i????????

I have a really nice looking shower with a really annoying dribble effect? I have heard that you can get shower pumps to boost the water pressure which connect onto the hot water cylinder.

Can any kind person confirm whether this will improve the rate at which the water is forced out, and also and recommendations would be appreciated.

Thanks,

Nigel

[Andy Hall]

Yes it will do as long as the plumbing is done correctly.

The important thing is that 22mm pipes are used throughout, especially on the input side of the pump. You can perhaps do the last metre or so to the shower valve in 15mm if needed.

Shower pumps do not like sucking. Preferably install the pump in a location such that the main runs of pipe are on the output side for this reason.

Also, install the pump relatively low. The airing cupboard floor is usually a good bet. The loft is not.

It is well worth investing in a good quality pump, and for that, I would recommend Stuart Turner. These are a very solidly engineered British made pump for which you can easily and cheaply get spares if ever needed. You will spend a little more than in the DIY sheds but can shop around for price.

.andy

To email, substitute .nospam with .gl

[IMM]

Nothing wrong with the loft as long as the pump is on the loft floor below the cold water tanks water level and the inlet pipe goes back to the cylinder, not teed off the open vent pipe.

[Ian Middleton]

I used a Techflow pump on floor of airing cupboard.

Had 22mm feeds, mostly 22mm outlets with last bits in 15mm. See the website for how to plumb in. I put a air release valve in the hot loop from tank to pump as in my previous house had suffered from air getting trapped and stopping the pump working.

On thing to bare in mind is you will need to make sure you mixer valve(s) can cope with the increased pressure, the original ones fitted to my house were LP (low pressure) and the valves suffered from lack of temperature (and flow) control as the pump just forced both hot and cold open. Changing to a HP (high pressure) valve (in same fixing) restored control to the flow and temperature. Some shower valves (Mira ?) have a plate that can be adjusted to tell the valve if incoming supply is low or high pressure, which is a better solution.

[Tim Mitchell]

In article , IMM writes

The problem is, that will put the pump at a high point in the pipework and it will keep getting airlocks in the hot side. At least, ours did, if I did it again I would install the pump low down.

[IMM]

An auto air vent on the pressure side of the pump will sort that. You don't need an auto air vent if you purge the line of air by loosening a pump union. Any air left in the loop will be pushed out using a high pressure pump. The only time air will ever enter again will be when the cold tank runs dry.

[BobS]

Have you thought about using a _venturi shower_ These use the mains cold water pressure to increase the output of the hot water. No electrics involved. HTH BobS

[John Stumbles]

I've done it both ways and can confirm that having the pump a few feet lower helps. It was on the loft floor, as also was the cw storage tank: it mightn't have been so bad if the tank had been a couple of feet higher up. I then moved the pump into the airing cupboard; not on the floor of the cupboard (there wasn't enough room) but on the first shelf above the cylinder, and it works much better there. As I recall the problem was that the flow switches didn't always kick in at some settings of the mixer valve and sometimes the pump would run intermittently. This may have been caused by air getting trapped in the pipework but I didn't think of a way to determine that for sure.

The hot feed is taken off the hot distribution pipework somewhere around the bottom of the airing cupboard and the cold feed from its own tapping from the cw tank. All pipework is in 15mm plastic. With all respect to Andy[1] I wouldn't go for 22mm pipework except, possibly, I had a very long run on the input side and/or the pump was mounted high up wrt the tank.

The pump I'm using is a Watermill with LV transformer which cost about £180 (IIRC). The only reason I used that is I already had it left over from another job. I haven't used Stuart Turner pumps but expect they might be quieter and possibly last longer than cheaper ones (spares are available for Watermill too, though not for some other cheap makes). Mounting pumps to keep the noise acceptable is a bit of a black art.

[1] coz he's bigger than me ;-)

[Nick Portalski]

My pump is also on the bottom of the airing cupboard floor, with the feed coming off the top of the hot water tank and a (short) run down from the cold water tank.

All the pipework (mix of plastic and copper) is 15mm - there haven't been any major problems (2.5 years). Having said that, we only run it at 'half' setting (you can change the pressure on our pump); full setting was a bit too forceful!

The pump is a NewTeam one - very occasionally the pump keeps running when you turn the mixer off - first time it happened I ran round looking for where the water was shooting out - now assume it's a bit of air as there's no water leak. Turning it on/off a couple of times stops it.

Nick