Vaillant Ecotech Plus 824

clearing_out_my_pockets

Hi - before I launch into our problem, a bit of background...

I bought a 'new' house late last year, completing on 23rd December. We took out boiler cover (Vaillant 3*) via homeserve just in case we got any problems. The previous owners had a new boiler installed in late January 2009.

Now the problem.

On Tuesday night, I came home and the boiler had shut itself off - error message on the panel said "F.23" and the pressure was down to 0.6 bar. OK, so we topped up the system and all was fine.

Yesterday morning at 7.20 the error message came up again. Only the pressure was at 1.8 bar, so should have been fine. Pressed the reset button and the fault code went.

Last night, OH got home and the fault code was back. Pressure at 2.0bar and the heating was on. Again, pressing the reset button cleared the problem.

This morning OH got up and there was no hot water. Sure enough - F.23. Pressure at 1.3, radiators struggling to reach the set temperature.

So... I called Vaillant and asked if we were still in warranty. Apparently you need to have a service within 13 months of installation to be covered, BUT they could come out and do the service and repair at the same time. Apparently they're waiting to hear from the insurers as to whether this is ok.

Anyway, I have no idea what the problem is and whether it's going to be easy to fix. Does anyone have any ideas?

chrissyfp1

Hi, I have the same boiler and have just looked at the servicing guide.

An F.23 error code means... Water shortage, temperature difference between flow and NTC too large....
Causes...... Pump blocked or defective, pump output too low, flow and return NTC interchanged.

I have no ideas how to fix it but thought the meaning of the codes might give you a little idea as to what's going on. HTH.

C_Mababejive

I wonder if the installer flushed out the system thoroughly before fitting the new boiler?

A water quality test might be interesting. Mr Vaillant might do that.

clearing_out_my_pockets

C_Mababejive wrote: »

I wonder if the installer flushed out the system thoroughly before fitting the new boiler?

A water quality test might be interesting. Mr Vaillant might do that.

Thanks - wouldn't the problem have been apparent before now? I admit to knowing nothing about boilers

gas4you

I've also had F23 when the the auto bypass in the boiler has stuck. Check this out.

It could just simply be a lack of flow through the boiler.

The pumps on these, tend to have a fault of leaking internally.

If the pump was not turning properly you would hear it.

gasbag1602

I think there is a modification you can have fitted that moves the position of the pressure sensor to eliminate this problem, it is normally used for boilers fitted to large systems but it would do the trick!!! I suspect though the system wont of been flushed properly and you will most likely have partial blockage in the flow/pressure sensor. In my experience flushing after the boiler has already been used on a mucky system for a while will not cure the problems, so you may need the kit too!!!

heating-eng

gasbag1602 wrote: »

I think there is a modification you can have fitted that moves the position of the pressure sensor to eliminate this problem, it is normally used for boilers fitted to large systems but it would do the trick!!! I suspect though the system wont of been flushed properly and you will most likely have partial blockage in the flow/pressure sensor. In my experience flushing after the boiler has already been used on a mucky system for a while will not cure the problems, so you may need the kit too!!!

Excellent post :T

clearing_out_my_pockets

Thanks for all your input.

I have spoken to Vaillant who are sending an engineer round on Tuesday to do the service so that the repair can be done under warranty. So far I've had to press the reset button twice in the space of an hour this morning - I have left it 'switched off'. Let's hope we don't get the predicted snow in the south east!

For the time being we're borrowing a halogen heater from my parents and resetting the boiler ten minutes before we want a shower or to wash up.

I've cancelled my boiler cover as the boiler is still under warranty and I'm paying for Vaillant to do the service.

gas4you

System muck in the pressure sensor usually gives an F75 fault code.

gasbag1602

gas4you wrote: »

System muck in the pressure sensor usually gives an F75 fault code.

The pressure switch is also a pump proving switch mate...regards alan

gas4you

gasbag1602 wrote: »

The pressure switch is also a pump proving switch mate...regards alan

Yes I agree. Thats why you get the F75. The board looks for a 0.2 Bar pressure increase when the pump starts to prove it's working.

Just now got back from a F75 breakdown as it happens. Muck in the pressure sensor.