Shower Pump fitting

[kevin12345]

Hi,
I'm trying to decide whether to fit a shower pump to my gravity fed shower doing the work myself.
My cold for the shower comes from the stored water in the loft tank and the hot comes out of the hot water cylinder and goes back up to the loft where then it runs parralell with the cold pipe back down to the ensuite shower.
I'm I correct in thinking that if I had a 1.5 bar twin pump it would just be a matter of redirecting the cold from the tank through the pump then to the shower cold, and also cut the hot in the loft and redirect though the pump then shower.
The instructions for the pumps I'm looking at (Salamander) say that the hot has to come from a no stop essex flange. This is the bit that is confuseing me, does it mean I have to fit one or would my set up be OK just to redirect the pipes like I said?
Thanks

 

[bookahandyman]

salamnder are very fussy if you ever have to call a warranty claim in. they will not touch unless all fitted correctly:-
surrey or essex flange from cylinder for hot supply,
water starvation switch unless >= than 80 gallon cold storage tank
independant cold supply pipie( taken from a point on cold tank lower than cylinder cold feed)
non return valves in supply pipes ( vertically positioned).

Although all of this should be done anyway. regardless of pump mfr.
Also if putting pump in loft you may get problems and require a negative head pump kit.
better to install in airing cupboard. and re route cold supply pipe to it and new hot supply from surrey flange to it.

 

[kevin12345]

Thanks for your reply, so what you are saying is that I could not just connect a pump on the pipe work already there.
I can put it in the airing cupboard next to the cylinder and drop the pipes from the loft then back up to the loft then to shower.
It is more involved then I thought it might be then.

 

[bookahandyman]

pumps prefer to push than pull (negative head) the water through the pipes. the surrey flange ensures no air gets in supply pipe if a hot tap is turned on at same time as shower is used.
the lower cold feed ensures that the hot will stop flowing before the cold , so that you wont get scalded if water runs low in tank.
Non return valves prevent contamination of potable water by back syphonage.
all these things are there for a reason, safety and water regs.
the hardest bit for you dependant on your skills would be re runnning the hot feed pipe from the surrey back to the vent/feed pipe, ensuring the same distance is maintained from water level to vent pipe in the tank and the gradient of supply from surrey to 't' peice in vertical is maintained.

 

[kevin12345]

I have done some plumbing before, new bathroom, kitchen etc but usually I'm more or less changing like for like. The termalogy you are using to fit the pumps sounds a bit confusing to me.
I think I understand the surrey valve. Would I need to fit non return valves before of after the pump?
Not sure I understand about maintaining the distances you were talking about.
How much do you think parts and labour would be for a plumber to fit?

 

[echoes]

Don't fit a non-return valve on the supply pipework to the pump, or an isolating valve unless it's full bore.

I did my shower pump on Friday, and used an Essex flange. Bit fiddly, but not difficult. [I did drop the copper disc cut out of the cylinder inside though. ]

 

[bookahandyman]

it would take a few hours to do and not including the pump probably around £50 in materials. depending on your plumbers hourly rate. I did one here a while ago and charged £225.00 for lab and parts , not inc pump that was already there.

the distance of the end of the vent pipe to the water level in the cold tank in loft is important and when you fit surrey flange the existing pipe off the cylinder ( you will note that it has a slight uphill run to a 't' peice. then goes up to the vent and down to the taps. ) will have to be moved about an inch or so higher to accomodate the surrey flange and keep the uphill run. therefore the vent pipe will have to shorten about an inch to keep the distance from water level in tank.and the tap supply pipe will have to extend a bit too.

it is quite complicated but not difficult. you just need to understand the principle of it first.

 

[kevin12345]

So Echoes,
What exactly did you do?
Cap of your hot branch that tees off to the hot shower
Drill your clylinder near the bottom, fit an essex flange,
send new hot to pump then reconnect to original hot going to shower.
What about cold from loft tank, did you drop that back to the airing cupboard into pump then back to shower?
Why did you not put in non return valves as other forum reader said?

 

[bookahandyman]

thats the problem with essex flange, the need to drill a hole in cylinder and the risk of dropping disc in the tank... if you do this way then put it about two thirds up the tank not at the bottom.and yes drain it all to below the hole location.

my apologies i totally forgot about iso valves ( use full bore on both supply pipes) i generally put one either side of pump on both supplies , ( enables removal of pump for maintenance and replacement.)

non returns are part of the water regs as are seperate feeds as sated previously.so are iso valves.

you'll have to excuse me now as ive just got back from Dubai and am shattered, my head is getting blurred now. will check in ya lata or tomoro.

 

[echoes]

So Echoes,
What exactly did you do?
Cap of your hot branch that tees off to the hot shower
Drill your clylinder near the bottom, fit an essex flange,
send new hot to pump then reconnect to original hot going to shower.
What about cold from loft tank, did you drop that back to the airing cupboard into pump then back to shower?
Why did you not put in non return valves as other forum reader said?

No existing branch to shower, but would have been capped off/removed if it existed.

Turn off water to cylinder cold feed, drain cylinder.
Drill cylinder 2" below the domed bit, fit essex flange.
New cold feed from loft CW tank down to airing cupboard in 22mm.

Salamander instructions say to NEVER to put check valve or restrictive ball valve, (among other things), on feed to pump. I did use full bore lever isolating valves.

 

[holty]

check with pump manufacturer,with regarding pipework. if the pipework is up and over. the likes of salamander require the cws to be higher, by about a foot. from the base, to the supply pipework. as mentioned i would put iso valves(full bore) on the feed and supply to the pump. or at least a couple of drain offs on the supply pipes close to the pump. with iso valves on the feeds.

 

[Richard C]

Absolutely nothing wrong with the advice you’ve been given so far but do a search for “shower pump installation” (or similar) & read the archive threads; lots of info in there much of it from me & it will help you understand more. If you have up & over loops you will need to vent the tops or you will constantly be fighting with air locks which will eventually damage your pump. If you run the loops from the pump closer than around 600mm to the bottom of the CWS tank, you could be in a negative head situation requiring a (more expensive) pump to suit. Separate 22mm feeds for the H &C pump supplies are best (in some cases essential) & the pump must be as close as possible to the water storage tanks with the shortest runs you can (there is a maximum & it aint very much). The CW feed should be fitted to the opposite end of the tank to the mains infeed. I would always fit an Essex flange which most pump manufacturers prefer as the best option. Never fit a check valve between the pump & the storage tanks. Salamander are OK (I actually have one) but fit an ST Monson for quality & I would fit a 2 bar minimum.

Unless you install the pump correctly (in accordance with the manufacturers instructions) it will give disappointing performance, will have a relatively short life & invalidate the manufacturers warranty, which is generally 3 years.