Vaillant EcoTec F22 error at night

[durhamwasp]

I've got a Vaillant EcoTec open vent boiler, and over the past week I've started waking up to a cold house and the F22 error on the boiler. Turn the boiler off then back on (or press ignition on boiler) and it fires up and works all day long, until the next morning.

I've got it connected to a Hive system, pretty much all day it's increasing or maintaining temperature on the schedule, but at 2300 I ask it to go from 20.5 to 20.0c... And so it isn't needed for a while, then usually around 1am the temperature has dropped to 19.9 and at that point it seemingly doesn't kick in and the F22 code comes up.

Go downstairs to boiler, reset it or click ignition and it works again..

 

[CountryFan]

Sounds more like an F22 on an open vented system. This is usually a lack of water, which can be multiple things. Pressing the ignition or turning off and on again, the pump (if built in) will add some pressure.

 

[DP]

Sounds more like an F22 on an open vented system. This is usually a lack of water, which can be multiple things. Pressing the ignition or turning off and on again, the pump (if built in) will add some pressure.

Does the OV Vaillant now come with built in pump option?. Asking as I am not familiar with this option. I thought OV bunnies had to have external pump

 

[CountryFan]

Does the OV Vaillant now come with built in pump option?. Asking as I am not familiar with this option. I thought OV bunnies had to have external pump

I don’t know tbh. This is what our customers have told me they do on the combi’s.

 

[durhamwasp]

External pump this one

 

[Teknet]

I've got a Vaillant EcoTec open vent boiler, and over the past week I've started waking up to a cold house and the F22 error on the boiler. Turn the boiler off then back on (or press ignition on boiler) and it fires up and works all day long, until the next morning.

I've got it connected to a Hive system, pretty much all day it's increasing or maintaining temperature on the schedule, but at 2300 I ask it to go from 20.5 to 20.0c... And so it isn't needed for a while, then usually around 1am the temperature has dropped to 19.9 and at that point it seemingly doesn't kick in and the F22 code comes up.

Go downstairs to boiler, reset it or click ignition and it works again..

Did you ever get to the bottom of this mate? I’m having the same issue - although it doesn’t do it every single night and has never done it during the day. I’m thinking it’s got something to do with when the ambient temperature outside gets cold it does something to the boiler as I’ve not really had any pressure drops.

 

[spile]

Assuming it’s a combi, what is the pressure in the radiator system? F22 is a low pressure code. If you’ve bled any radiators (often the highest one) without topping up the pressure may have dropped enough to cause the issue. I had this happen a couple of times and the pressure was ok and I put this down to gas/air in the system. Hence the need for inhibitor.

 

[Teknet]

Assuming it’s a combi, what is the pressure in the radiator system? F22 is a low pressure code. If you’ve bled any radiators (often the highest one) without topping up the pressure may have dropped enough to cause the issue. I had this happen a couple of times and the pressure was ok and I put this down to gas/air in the system. Hence the need for inhibitor.

No it’s not a combi boiler. The pressure in the system is 1.4 bar. Whenever I have bled the rads the pressure may drop to 1.3 in which case I top it up a little. I do also have inhibitor in the system.

The common denominator which I think could be related to this is the outside temp. On nights where it goes below 5 degrees o generally wake up to the boiler having tripped in the middle of the night and F22 showing. The boiler has never ever tripped during the day and it doesn’t trip every single night which is why I’m believing it’s something to do with the ambient temp? I’m really puzzled by this!

 

[Johntheo5]

The series 4 Vaillants are heat only boilers and as stated above have a external pump so have a look at its mode and setting.

 

[Teknet]

My boiler is actually a British Gas BG330+

The fault codes are the same as I’ve looked it up. The Grundfos pump which I have has been put on setting 3 which is its highest, and also the setting it should be on to expel and air in the system

 

[Johntheo5]

What is the exact model Grundfos pump? If its a 6M UPS3, then guaranteed problems running It at speed 3 if the pump is healthy, try speed 1.

 

[Teknet]

It’s a Grundfos Alpha 2…

I don’t think it’s the pump because as I previously said, it’s never tripped the boiler during the day, only ever in the middle of the night - sometimes not every night.

 

[Johntheo5]

Again, as stated above I think, the increase in pump press is a indication also that there is water in the system so I wouldn't, rule out the pump completely, especially if old, if the boiler has a pressure gauge then you should see the pressure increasing by around 0.2bar when the pump starts.

 

[Teknet]

I’m not sure I completely follow - you wrote ‘the increase in pump pressure’. I manually put it to level 3 after the boiler had tripped a few times that week. It doesn’t seem to have made much difference though