Trevi Therm and Stuart Turner Trevi 45 pump

[Cambridge Mum]

I have had these more than 10 years now, and the only problem has been the thermostatic cartridge which was replaced a few years ago. I have recently found out that the pipework from the pump should be 22mm but is in fact only 15mm. Since the shower's worked perfectly well for all this time, I am guessing the only reason 22mm is recommended is to increase the flow rate. The shower is perfectly adequate, although not a monsoon by any means. The hot water cylinder is only a torpedo. If the pipework were to be changed to 22mm, say when the pump needed changing, would I get a better shower, and would this be at the price of the hot water running out? I am hoping the pump will keep going for at least another ten years!

 

[Softus]

I have recently found out that the pipework from the pump should be 22mm but is in fact only 15mm.

That's less important than the gauge of pipework to the pump, since too much restriction may lead to cavitation.

Since the shower's worked perfectly well for all this time, I am guessing the only reason 22mm is recommended is to increase the flow rate.

Or, to be picky, to not decrease it.

The shower is perfectly adequate, although not a monsoon by any means. The hot water cylinder is only a torpedo. If the pipework were to be changed to 22mm, say when the pump needed changing, would I get a better shower, and would this be at the price of the hot water running out?

Only if you open the shower flow control some more.

I am hoping the pump will keep going for at least another ten years!

Don't let the pump hear you say that.