Vaillant ecotec plus 937 flood

[AMGasServices]

Hi guys,

I went out to a ecotec 937 showing error code f75. I thought ill check it the pump is ok. As I open the silver nut I was flooded with water is this normal?

Usually pumps only has a few drops of water dripping not a whole flood.

Secondly, can I just change the pump head or do it have to change the complete thing ? Customer is a single mum who is struggling to make ends meet.

Thankyou for reading.

Cheers

 

[stoker122]

F75 is no pressure rise on startup, usually blocked pressure sensor.
If the boiler is at 1-2 bar you will get a good amount of water coming out.
I think Vaillant changed the design of the pump so a new head won't fit on the original bodies

 

[AMGasServices]

Thanks stoker122 I went in topped up the pressure as it was low. The customer used the hot water and the PRV chucked it all out. Thats why I was thinking its the pump. It also senses the pressure.

 

[stoker122]

Did you check the expansion vessel?
Sounds like a good service is needed

 

[AMGasServices]

No, I'm gonna go back to check the expension vessel but there's no heating at all.

 

[CES]

Replace the pressure sensor (or unclog the port). The position of the sensor was changed.
Thats the first thing I would check, then the pump IMO.

 

[stoker122]

The 937 also has a Prv and expansion vessel on the 15 litre storage vessel that needs checking AMG.

 

[TBServices]

Don't Vaillant do an F75 kit to improve sensor position?

 

[AMGasServices]

Thanks for your reply everyone, I recharged the expension vessel. Then replaced the pump. The boiler fired up the heater exchanger was making a knocking noise so it's blocked and shows error code f28. It's not worth replacing the heater exchange.

 

[TBServices]

On a 937? Surely it can't be so old it's not worth salvaging. Get some x800 in for a week, flush the system and fit a mag filter.

 

[radswilldo]

Do a P0 test (bleeding program) before anything else. Ican't see how the boiler has gone from F75 to F28. 99 times out of 100 F75 is apressure sensor blockage/failure. F28 is ignition/Gas. Actually, given thenoise I would be tempted to drain the boiler, re-fill using P6 then run P0.Once done, create c.h demand and follow the stautus codes via the 'i' button,record the status numbers that appear. Let us know what happens!

 

[AMGasServices]

Thanks for all your replies folks. Got the good old dryer out and dried the PCB after a few hours the thing fired up. No more knocking noise thank The Lord for that. Glad everything is sorted.

 

[vern]

Lol glad its sorted, the 937 ain't cheap!

 

[AMGasServices]

Customer paint £1600 3-4 years ago.