Hello All,
Hoping for a bit of advice/info in this one:
My Setup
Small system in apartment with cold tank above hot tank in the hotpress, so fairly low head pressure. Installed a pump about 15 years ago and worked fine until last week (original pump was an Stuart Turner ST55 replaced after approx 10 years with an ST20 2 bar).
The pump feeds 2 basins (bathroom hot & cold, kitchen sink hot only) as well as the shower/bath tap. Its extremely rare (or never) that the pump would be feeding more than one tap at a time.
I'm aware that I should probably have a negative head pump, but I've always been able to start the shower by lowering the shower head until flow is established, no problem, so the huge cost difference didn't seem worth it.
The Problem
In the last week only - I'm finding that when running the bath/shower tap, I can run hot water no problem but as soon as I introduce a little bit of cold water, the hot cuts out and the pump seems to stall on the hot side. This happens regardless of whether I'm filling the bath or directing the water to the shower.
I should say that both hot and cold run absolutely fine when run at the same time through separate taps, this problem only happens on the bath tap when mixing hot and cold.
What I've tried
I've opened up the bath tap by unscrewing the redirection knob (the thing that you pull up to change from bath to shower) to check for debris - nothing. I've also taken out the hot water cartridge and it looks fine. No blockages in the shower head or line feeding it either.
I figured it must be the ST20 pump, so I bought a replacement Stuart Turner showermate 1.5 bar positive head regenerative twin model, confident that this would sort the problem.
The problem still happens with the new pump.
My Questions
Anyone got any idea whats happening?
Is the problem likely to be the bath tap?
If I replace it, would I be better buying a more expensive model with a mixer cartridge built in? (this is in a hard water area so I want to avoid maintenance of cartridge if I can)
Any and all help greatly appreciated!
Hoping for a bit of advice/info in this one:
My Setup
Small system in apartment with cold tank above hot tank in the hotpress, so fairly low head pressure. Installed a pump about 15 years ago and worked fine until last week (original pump was an Stuart Turner ST55 replaced after approx 10 years with an ST20 2 bar).
The pump feeds 2 basins (bathroom hot & cold, kitchen sink hot only) as well as the shower/bath tap. Its extremely rare (or never) that the pump would be feeding more than one tap at a time.
I'm aware that I should probably have a negative head pump, but I've always been able to start the shower by lowering the shower head until flow is established, no problem, so the huge cost difference didn't seem worth it.
The Problem
In the last week only - I'm finding that when running the bath/shower tap, I can run hot water no problem but as soon as I introduce a little bit of cold water, the hot cuts out and the pump seems to stall on the hot side. This happens regardless of whether I'm filling the bath or directing the water to the shower.
I should say that both hot and cold run absolutely fine when run at the same time through separate taps, this problem only happens on the bath tap when mixing hot and cold.
What I've tried
I've opened up the bath tap by unscrewing the redirection knob (the thing that you pull up to change from bath to shower) to check for debris - nothing. I've also taken out the hot water cartridge and it looks fine. No blockages in the shower head or line feeding it either.
I figured it must be the ST20 pump, so I bought a replacement Stuart Turner showermate 1.5 bar positive head regenerative twin model, confident that this would sort the problem.
The problem still happens with the new pump.
My Questions
Anyone got any idea whats happening?
Is the problem likely to be the bath tap?
If I replace it, would I be better buying a more expensive model with a mixer cartridge built in? (this is in a hard water area so I want to avoid maintenance of cartridge if I can)
Any and all help greatly appreciated!