shower pump woes

[tomplumb]

right, i have a salamander ct-50 shower pump i installed for a mate of mine .. hot water is coming from cylinder located in the bathroom where the pump is .. and cold is tank fed from a tank directly above the cylinder which gives around 6ft of head

the pump started to leak out of the body on the cold side .. so i had a quick look and decided to replace with a new one .. the pump is now doing the exact same ..

wen the cold is turned on the shower splutters quite alot .. i have teed it into the tank fed cold feed that goes directly to the toilet .. is that the problem do you think? the spluttering i mean .. and do you think the spluttering is causing the pump unit to leak?

its doin my nut in hah

any feedback would be great guys cheers

tom

 

[Mike Jackson]

The pump should be on a dedicated cold feed. It's probably drawing air in from the float operated valve on the toilet cistern. The bearings on these things are normally water cooled and a lot of air can cause them to overheat. that or the vibrations could cause a case failure.

Mike

 

[buffy27]

while waiting for the more experienced guys to help u .i'll give u my penny s worth if its of any use.from what i know,{have nt done one myself.} supply should b direct from storage tank for cold.surrey flange should b on the hot out of cylinder.the pipes in and out need to b of specific bore depending on pump model.

 

[tomplumb]

yeah im thinkin it is the tee thats messin me up drawing air in .. any way i could get around this without going back to the tank to run an independant cold feed?
would a non return valve fitted after the tee n stop air coming back to the pump ya reckon?

thanks for you help guys

tom

 

[Phil]

Tomplumb, did Salamander send you out a new pump or did you buy another one?

If Salamander sent you a new pump they would have asked if the CT-50 had been installed exactly to their specifications (they are quite strict about this to protect themselves) and only send a new one out if their satisfied its been installed corectly because pumps do not like air.

If the cold water feed to the toilet (tank fed) has a non return valve fitted to it , it will reduce the flow to the toilet so you're just making things worse. I would strongly recommend you get yourself a 22m tank connector and some 22mm copper pipe and do the job right.

Also don't forget the air vents at the high spots on the pump feed pipework.

It is very important the hot and cold have their own dedicated feeds and the cold water storage tank is a minimum 50 gallons which if the house has indirect cold water (all cold taps from tank except kitched tap) then it should have.

How have you connected into the cylinder? surrey/essex?

 

[NickH]

Something else to bear in mind, when the pump kicks in and "sucks" the hot water from the cylinder it will cause a pressure drop in the cylinder and pipework, if the water is above a certain temperature and depending on the power of the pump this pressure drop can be enough to cause the water to boil up so causing the formation of air bubbles in the pipework. I had this exact problem a few years ago and was advised by the pump manufacturer to have the cylinder stat at 60 deg max. I had spent hours and hours trying to stop air getting into the system and all it needed was a turn of the stat.

 

[Phil]

I think I'll write that one down......

 

[NickH]

That particular job had me completely stumped, i was convinced air was being drawn in somewhere, i even replaced the cold feed to the cylinder as i thought it may have been sucking air down the vent because of a blocked feed, a couple of plumber mates had no ideas so I eventually phoned the tech helpline. It was actually the Surrey flange manufacteres helpline and he new instantly what it was, apparently a pretty common problem.
I had a similar problem on a later occasion, a second floor flat had a bathroom with all supplies pumped, when you ran a hot tap the pump would start but when you shut the tap the pump would switch off but than flick on and off repeatadly. The pressure drop was causing the hot water to boil and when the tap was closed the water was "bouncing" because of the air in the pipework, this was enough so activate the flow switch on the pump and hence the on/off cycles. That had me stumped for a while until the penny dropped and i remembered the previous problem.
My own shower occasionally suffers slightly from this problem if the cylinder is fully hot, but only for a minute or so until the hottest water has been drawn off, and my stat is only set to 55 deg

 

[Brooksie]

I replaced a leaking shower pump with the CT50 and it spluttered badly. Stop start every 2 or 3 seconds and occasionally stopping completely after 1 or 2 mins. After much faffing about and changing pipe runs etc I took the plastic restrictor disc out of the 'rain water' type shower head (approx 7 inch diameter) and all was well. It went from 4 ltrs / minute flow to 8 with no spluttering. Before there was spluttering only with a hot shower and it worked fine on a warm or cold shower.

Brooksie

 

[tomplumb]

thanks alot guys! im goin back this week and try a few of these ideas .. but like someone said above .. pumps dont like air and it caused the ct50 to leak with it turning on and off every 2 or 3 seconds ..

ill check the stat too like dont want no boilage!

thanks guys as usual a great help!