Salamander Pump Problem - Hot Water

[adamsh]

Hi All,

Have searched and searched the forum for this particular problem and whilst I can see many other queries and problems related to Salamander pumps, I can't see any that are the same as mine.

I have a Salamander ESP 75 CPV twin fitted in the airing cupboard on the floor next to the hot water cylinder. The pump runs all of the upstairs outlets (2 x basin, 2 x shower, 2 x toilet cisterns and a bath) as well as two hot taps downstairs. All has been fine for over 4 years (except that the seals on the hot side of the pump needed replacing about 18 months ago). Last night, the pump suddenly made some additional noise while running - didn't sound good, and the immediate symptom was that the hot water had less pressure than the cold at all outlets. Annoying, but not the end of the world. Today though, there is a also a problem with the temperature although the noise problem has gone. To cut a long story short, I've determined that the hot water is perfectly hot at all outlets when the pump is off, albeit not at anywhere near decent pressure of course upstairs. When the pump is turned back on, the pressure returns but the previously hot water soon turns lukewarm at best. Turn the pump off and the water slows but gets hot again. And so on...

Will speak to Salamander tomorrow but any clues in the meantime would be much appreciated.

Cheers,

 

[Richard C]

Hi All,
Last night, the pump suddenly made some additional noise while running - didn't sound good, and the immediate symptom was that the hot water had less pressure than the cold at all outlets.

Difficult to say for certain but my money would be some form of internal damage to the impeller on the h/w side of the pump. Only way to tell for certain is to remove the pump & stip for internal inspection. I would avoid running it further; it may be capable of repair a the moment but if you continue to run it, you may totally destroy it internally.

 

[adamsh]

Agree entirely that there could be a problem internally. The pump is off (low pressure hot water preferable to high pressure lukewarm water!) so that should limit any further potential damage.

Still can't understand though why the water is hot with pump off, but lukewarm when it's on.

Was since wondering if it's being cause by aeration from somewhere? Could the flange on the HWC have suddenly failed in some way thus allowing too much air into the hot water when the pump is running?

cheers,

 

[Richard C]

Anything is possible I suppose but rather unlikely; a side entry Essex flange is just an upturned lump of 22mm pipe so not much to go wrong there. Top entry flanges are also extremely simple & practically the only thing that can go wrong is the feed tube or deflector falling off but, again, I would think it unlikely.

Poor system design can give problems with air accumulation or air locks but the fact that your system has been working fine for 4 years & only started giving problems after the pump “made a nasty noise” would give a pretty strong clue to me. It’s worth a try bleeding the pump I suppose; simply loosen the pump connections & allow the water to run into an old towel.