Problem with pressurised system

necstandards

We upgraded our water system to a zoned pressurised system three years ago, part of the SEAI grant. All has been working fine until lately where I notice the pump (Grundfos MQ 35 I think) seems to be cutting in a lot more recently. For test purposes I fully open one hot tap, the pump runs for 13 seconds, stops for 6, runs for 13, stops for 6 and so on.

I’ve checked the pressure in the expansion thank and it seems to be ~2.5 barg. Not sure what else to check – any advice would be welcomed.

Calahonda52

My guess its the capacitor is getting to the end of life.

I just replaced mine, Wilo

If you are anyway handy working with elec, its a DIY job once u source the exact piece.

The pressure in the exp vessel needs to be tested when system is at atmospheric pressure, switch off pump, turn off cold feed and run taps to empty.
Check the charge pressure on the vessel online

rightjob!

necstandards wrote: »

We upgraded our water system to a zoned pressurised system three years ago, part of the SEAI grant. All has been working fine until lately where I notice the pump (Grundfos MQ 35 I think) seems to be cutting in a lot more recently. For test purposes I fully open one hot tap, the pump runs for 13 seconds, stops for 6, runs for 13, stops for 6 and so on.

I’ve checked the pressure in the expansion thank and it seems to be ~2.5 barg. Not sure what else to check – any advice would be welcomed.

is there valves on the outlet side of your pump?
if there is shut it off and see does the pump kick in and out..this will let you know if its your plumbing or pump.

also check in all the toilet bowls to see if the syphons are passing water,usually the case

necstandards

Yes, there are ball valves on both the supply & return to the pump. So i'll close both and see what happens. tks

necstandards

Called Grundfos today, they recommend the flow sensor be replaced.

At ~€65 i hope they are right!!!

rightjob!

necstandards wrote: »

Called Grundfos today, they recommend the flow sensor be replaced.

At ~€65 i hope they are right!!!

did you close off the outlet from the pump?is it still running when u do this?

necstandards

The problem only happens when there is water being drawn off (maybe i didnt make that clear) so on that basis, i dont think closing the pump outlet will help tell anything?

cruiser202006

necstandards wrote: »

The problem only happens when there is water being drawn off (maybe i didnt make that clear) so on that basis, i dont think closing the pump outlet will help tell anything?

Did u turn off the pump and drain off the pressure. In other words is that 2.5 bar with the pressure in the system?