Stuart Turner Mainsboost Pump won't stop running

[rossyl]

Hi All,

We have
1. Stuart Turner Vessel Mainsboost
2. Stuart Turner Mainsboost Charger 44725 mbc12-22WM (wall mounted pump)

Also a Vaillant EcoTEc 630 and MegaFlo Invented cylinder.

The wall mounted pump runs continuously and burnt itself out.

I have check for leaks and not found any. Leave everything off in the house the water meter doesn't move in an hour. But flush the toilet and I can see the meter move immediately.

Any ideas what could be causing the pump to run continuously.

We have had Stuart Turner out and they aren't sure either. They replaced the pump and the same thing happens. I drained the tank, but no improvement.

It worked fine for 9 months then one day the pump just would not stop running.

Grateful for thoughts.

Thanks

 

[Madrab]

Tests - only way to see what's going on -

Fit output valves (appliance valves will do) along the mains supply from the pump. Fit a pressure gauge to the first valve and activate the pump, if the vessel/pipework isn't coming up to the desired set point pressure and holding then the pump will run constantly. The pump should also have a max Pump run time and heat max temp set point that allows the pump to auto shut down when either are exceeded, exactly to stop the pump from burning out, are these not setup?

Presume there is a pressure vessel as part of the setup - accumulator?