Salamander Pump - Help

[brittas2009]

Hi, we have a Salamander force 20tu pump that provides pumped water to our shower and also our bath. We've recently experienced a problem whereby the water gradually decreases in temp as you use it and also pressure ....just to explain, person 1 has a shower and that's all fine. Person 2 then uses it straight after and suddenly the temp starts to reduce to the point where it's cold and there's a lack of pressure too...The system is gravity fed and there's still Hot water in the cyLinder - I know this because the basin isn't fed from the pump and hot water still comes out of the hot tap. I had Initially thought the issue would be the shower thermostatic valve so replaced that but the issues persists - I've also since tried the bath where the water is delivered via a mixer spout and the result is the same -cold!....so I'm thinking at this point that it must be pump related. It's out of warranty so I'm on my own... I was wondering if anyone had come across this problem in the past??....all our water is softened so I'm guessing shouldn't be scale.....I'm thinking it could be a fault related to the pump as it gets warmer but would be grateful of any advice.

Many thanks


Brittas

 

[oldbuffer]

If your shower pump hot inlet side is fed via a Surrey, Warix or Essex flange, or similar, as it should be, the feed will be from a little below the top of the hot water cylinder (HWC), to avoid air being pulled into the pump. If the amount of water you use is sufficient to almost empty the HWC, the water going into the shower will be cold, but the remaining couple of inches at the top of the tank will be hot. This will be going into the wash basin hot tap, and is possibly why that tap still runs hot. If you look up the various flanges on the internet you'll see how they work.

If the above is the cause it may be occurring because:
a. you are taking longer showers. Cure is shorter showers or a bigger HWC (and probably cold water storage cistern as well).
b. the water in the tank is no longer as hot as it used to be. As a result the mixer is using more hot than before to achieve the desired output temperature. Identify and fix reason for cooler water. Boiler temperature turned down? Cylinder thermostat turned down? Could be a number of things.

 

[brittas2009]

Hi, thank you for your help. It's set up with a Surrey a Flange. The amount of HW did run through my mind but we've never had that problem before - Mrs B takes ages but that's never been any different.....it's odd how the pressure drops away too and wondered would you experience that too with the lack of HW?.....I had assumed it would continue to pump out the same volume, albeit cold?. I've checked the cylinder thermostat and will run the boiler until it cuts out on the stat, which is set to about 56 deg and see if that makes a difference too.

Many thanks

 

[brittas2009]

Btw, I've checked the Cold water tank and there's a shed load of water in there too!

 

[oldbuffer]

56 is a bit low for the cylinder thermostat. I'd try it on 60 to 65 and make sure the boiler flow temperature when on hot water is 5 degrees or so hotter than the cylinder thermostat.