Boiler - HW stops, pressure & temp goes reading increase dramatically

[Flash74]

Hi all,

Wonder if anyone can help any advice welcomed. Problem with a Valliant Turbomax 828e, whilst the boiler is supplying hot water (also usually the heating is on when it happens, also i think it happens when another tap is turned on)

symptoms

1. The hot water tuns cold.
2. The boilers pressure gauge goes up from around 2 to 3 bars
3. the temperature display on the boiler increase rapidly from 70 to 130 (think 130 is the cut off hence cold water).
4. After 3 minutes the temperature drops including the pressure, at which point you can hear a rush of water in the boiler, this happens faster if the reset button is pressed.
5. The boiler works fine.

I have replaced the diverter valve and secondary heat exchange, which has stopped a F22 - water error but this problem is still happening, apprently its once every other day rougthly

Any help really appreciated

Cheers

F

 

[newbie1]

could be there is a blockage...have you tried powerflushing if divertor and plate heat exchanger are new then can only assume water is getting blocked elsewhere

 

[REDSAW]

f22 - water pressure???
i thought that was no gas?.

 

[Flash74]

Cheers guys, I believe F22 is no water, ever seen seen the temp and pressure jump up? Will try a power flush. Pressue to house is great, 15 mm to and from stop tap to boiler. Boiler is 1 meter from tap. Any other ideas?

Cheers

F

 

[REDSAW]

yes, sorry i was thinking f28.
f22 is loss of water pressure i believe.