F22 on Vailant 824E Boiler

Hi,

My Vailant boiler regularly comes up with F22. When I turn it off and on, it clears it and the hot water starts again. It appears to occur when you run a hot water tap slightly open. Boiler pressure etc is OK. This has been the case for a few years, it is nuisance especially first thing in the morning.

Any ideas, much appreciated.

Thanking you.

SRW

The manual will tell you what F22 means. Maybe in a few more years you might look it up? No rush, but if you haven't got a manual, you could try this -

http://www.vaillant.co.uk/stepone2/.../turboMAX_plus_thermoCOMPACT_installation.pdf

I usually look them up if its important.

I think that may be a fault code actuated by too great a temperature diffferential across the primary heat exchanger.

It may be caused by sludge or other blockages in the plate HE, main HE or pump.

Obviously I dont understand people who allow their cars and boilers to go on for years with an obvious fault but do nothing to get them fixed.

I like all my things to work properly all the time!

Tony

Can be due to flow and return thermisters going out of spec. Early PCB's can produce the F22 due to bad design (ie they interpret the temperature differential across the main heat exchanger as being too steep).

Unfortunately Vaillant tech can't tell you the serial numbers of the later "fixed" boards.

Or as Tony said sludge and scale in the system.