Glow Worm CXI 30 DHW problem

Hi Guys,

I've got a glow worm 30 CXI which was installed in 2003, which has worked really well till about 4 weeks ago.

The problem is that the hot water is not that hot any more, so I turned it up on the boiler. The hot water then got hot but its cuts off after about 2 minutes of running. The boiler then displays a F9 fault, which flashes for about 10-15 seconds then the boiler restarts.

This fault occurs on the top 20% of the dial only. turning it down you don't get the cut out, however the water is not hot enough!.

I've checked the thermistors and these all read correctly. Putting a voltmeter across the CH flow thermistor when the problems occurs, gives a reading off 0.88 V at the point of trip.

Looking at the manual the F9 code states Pressure Sensor failure. I've put a meter on the pressure sensor and I get a steady 1.72 V, during operation and at the point of the trip.

My system was a total new one at the time of installation, and has had inhibitor in since new, I have however recently had a few raditors off and on again to decorate.

The CH works with out fault.

Can anyone help with this problem

Thanks in Advance

Nick

Blocked plate heatexchanger F9 on your age boiler is a generic code.

gasgeezer said:

Blocked plate heatexchanger F9 on your age boiler is a generic code.

Click to expand...

Hi,
Thanks for the Advice, is there somewhere I can find info about cleaning the Plate Heat exchanger?

Also I made a small error the boiler was installed in 2003 not 2000

Cheers
Nick

I Removed the Plate Exchanger and washed out the black gunk with a high pressure hose and boiler works great.

I expect there is a better way to do this, but the hose worked for me!

Thanks for the advise

Nick