Shower pump lifespan

[adwt2004]

Hi guys,

I have a shower pump (RSP75) which powers two showers at the moment. It's now out of warranty and I want to use it to power hot taps as well.

I know it's not designed for that but my view is to use it in a non designed config until it breaks and then replace with a house pump instead.

Do they fail in a spectacular fashion or could I get away with this for a period of time?

 

[Gasguru]

AFAIR the RSP range is only designed for showers etc where both the hot and cold flow will be in use at the same time.
If you use it with a basin where it would be possible to dead head one side of the pump (ie. run it with just the hot or cold in use) the friction of churning the water in the closed side can create sufficient heat to pop the pump seals (friction heats water..excessive pressure blows seals).
That's why some pumps are designated "whole house" etc and are manufactured with bypass devices or alternatives.

 

[adwt2004]

ok, probably not a good idea then. So either fit a single impeller model for that purpose, or swap out what I have for a whole house alternative. Darn.

 

[Gasguru]

Or make sure you always have a little flow on the tap not being used.

 

[adwt2004]

Yeah could do. I would rather swap it for a house pump but we’re talking over £200. Wife says hell no! Our current pump is in good condition and seems a shame to remove it. Resale wouldn’t be great for it either.

I’ve looked at those Grundfos UPA 90 boosters that sit in line but no experience of them. That way I could run two pumps but not have a load of pipe work in the cupboard. They seem discontinued but are still available new.

https://plumbonline.net.au/grundfos-upa-15-90-n-160-stainless-steel-domestic-home-booster-240vpumps/

 

[Gasguru]

I suspect those Salamander pumps are made out of recyclced yoghurt pots....the impellers are very prone to warping if they overheat so make sure your water can't exceed 60 odd degrees. I've had the impellers weld themselves to the casing when the immersion heater thermostats have failed.