Advice needed for fitting a pump

[Gavin77]

Hi guys.
Need a bit of advice about a shower pump.

My parents have now got two bathrooms in their house and its on a standard gravity fed system. The pressure on the shower in the 2nd bathroom is appalling, and the 1st one isn’t much better, and it looks like I’m going to have to go and sort it out.

I’m thinking the easiest way is a whole house pump from wickes, but does this give problems elsewhere? I assume that when you flush the toilet the pump will start running, which may or may not be annoying depending on how noisy it is.

Also if a whole house pump is fitted, is a Surrey Flange needed or is it simply a case of placing it in line with the outlet from the hot cylinder and the cold tank before it starts teeing off everywhere.

If anyone here has a whole house pump, would they recommend this or are there problems?

Cheers guys

Gavin.

 

[kevplumb]

if its only the showers that are the prob just pump them

if you do use a whole house pump feed the wc/s seperatly from the tank

no doubt know it all goldberk will tell you different

once he has trolled the web for an answer

 

[Gavin77]

Hi Kev. Yes it is just the showers that are the problem.

The work involved in just pumping the showers is quite large. But your advice would be to get a pump which could do both showers, run a seperate feed from the cold water tank to the pump, and a feed from a surrey flange or similar for the hot to the pump?

What are the problems with simply "pumping the whole house"

 

[kevplumb]

What are the problems with simply "pumping the whole house"

none apart from the wc/s i would keep them seperate

and check the amount of stored water you have as well

don't take long to empty a tank when both hot and cold are coming out of it

 

[BingoBongo]

make and model of showers would be a start

 

[kevplumb]

doh

 

[Gavin77]

OK Cheers Kev.

BingoBongo, they are just standard mixer valves, i can find out make and model, but dont really see how that will help. The problem is a general lack of pressure in the gravity fed system, made worse by quite a long run of pipe to the 2nd bathroom.

Hmm i wonder what is involved in raising the water tank.

 

[Gavin77]

I've read a few other posts here where powershowers have been "Tee'd off the bath taps" rather than having a dedicated feed and have "got away with it"

So that got me thinking about another option. If I put in a smaller pump, such as the Salamander CT50+ and locate this in the 2nd bathroom, would this work? There would be about a 5 metre run of pipe on the suction side, and im hoping that this run would be enough to prevent air being sucked down the vent pipe. Or would i get a problem with cavitation? Any thoughts?

Can the power or speed of these pumps be adjusted? We're really not looking for power shower performance here, 0.5 bar would be plenty.

 

[kevplumb]

So that got me thinking about another option. If I put in a smaller pump, such as the Salamander CT50+ and locate this in the 2nd bathroom, would this work? There would be about a 5 metre run of pipe on the suction side, and im hoping that this run would be enough to prevent air being sucked down the vent pipe. Or would i get a problem with cavitation? Any thoughts?

sounds ok

 

[Goldberg]

I've read a few other posts here where powershowers have been "Tee'd off the bath taps" rather than having a dedicated feed and have "got away with it"

So that got me thinking about another option. If I put in a smaller pump, such as the Salamander CT50+ and locate this in the 2nd bathroom, would this work?

If your question is "Would it pump water?", then of course it would.

There would be about a 5 metre run of pipe on the suction side, and im hoping that this run would be enough to prevent air being sucked down the vent pipe. Or would i get a problem with cavitation? Any thoughts?

If your question is "Would it draw air down the vent?", then you'll have to try it and see.

If your question is "Would it cavitate instead of drawing air, because of the increased resistance on a long run of pipe?", then you'll have to try it and see.

Put it like this - if you buy a cheap pump and install it such that it has a reduced lifespan, but it works, then all you've lost is the price of the pump. If buying a pump every year (or whatever) is cheaper than running new dedicated (pumped) services to the shower(s), then it's clearly the right compromise for you.

 

[Gavin77]

I didnt realise the Salamander CT50+ was a cheap pump, it seems to have good reviews. If you can recommend me a better one then im all ears.

As long as the pipework doesnt cause cavitation, I cant see how a long suction run can reduce the lifespan of the pump

 

[kevplumb]

If your question is "Would it draw air down the vent?", then you'll have to try it and see.

If your question is "Would it cavitate instead of drawing air, because of the increased resistance on a long run of pipe?", then you'll have to try it and see.

really helpfull advice (as usual)

nothing wrong with salamander pumps

ignore the lemon

 

[Goldberg]

I didnt realise the Salamander CT50+ was a cheap pump, it seems to have good reviews. If you can recommend me a better one then im all ears.

You need a compromise because you can't afford to do the re-piping work, so I wasn't suggesting that you shouldn't use that pump - I was encouraging you to use it.

As long as the pipework doesnt cause cavitation, I cant see how a long suction run can reduce the lifespan of the pump

A long run increases the risk of cavitation, but on a smaller pump I don't expect this to occur. The pump is designed to be more efficient at a higher dynamic pressure on inlet, so I was just pointing out that you can't reduce one risk (i.e. that of drawing vent air) without increasing another risk (i.e. that of cavitation).

The bottom line is that IF your pump wears out more quickly than it should, then that's the only possible detrimental effect, and routine replacement probably matters to you less than having to do a lot of work just to extend pump life.

 

[kevplumb]

The bottom line is that IF your pump wears out more quickly than it should, then that's the only possible detrimental effect, and routine replacement probably matters to you less than having to do a lot of work just to extend pump life.

the bottom line is your talking carp again goldberk

 

[Gavin77]

OK guys we've had a think about this and i've decided that if I am going to fit it, its going to be done properly. So heres what I intend to do.

Salamander RSP 50 Shower pump supplying two conventional showers.
22mm cold feed from loft tank, 22mm hot feed from Essex Flange.
15mm pipework from pump to both showers.

I have a couple of querys based on the installation instructions though.

1. Hot water cylinder feed should be in 28mm. Currently its 22mm, and it looks like the tank connector is only 22mm, so what should i do here? Should the pipework be increased to 28mm, then reduced at the tank connector to 22mm?

2. It says that the hot and cold supplies must be exclusive to the pump, but doesnt really mention about the hot cylinder feed (Other than it should be 28mm) Currently the hot cylinder feed is in 22mm, and feeds the cold supply as well as the cylinder. Does this now mean I need three feeds from the loft tank? (1 for the cold inlet on the pump, 1 for the cylinder and 1 for the non shower cold water?) Or can the 28mm feed supply the cylinder and the cold service?

Thanks for any advice.

Gavin