My initial response in all issues with heat pumps is to check the filter and see if it’s restricting flow. I’ll pass your issue over to Vaillant tomorrow.

Is the message really that you need to contact a “competent” person. That’s really funny if it is. 

Yup that's exactly what it is telling me! 🙂 Just got a fault code of F.788 (pump) from the main unit in the garage.

Posted by: @witchcraft

Morning, My ASHP has decided to switch itself off this morning, the SensoCOMFORT reports "Mode: Back-up Boiler if fault occurs.  HP Call the competent person."

As my competent person is my bankrupt installer and we don't have a back up boiler I have no idea what to do (Vailant's help line doesn't open until Monday).  System water pressure is good and the HP was working fine until 45 mins or so ago.

Any ideas.

 

Looking at the manual it would appear that F.788 is in relation to the water pump external to the heat pump unit. Try carrying out the checks detailed in the fault code list.

Also try the reset procedure as detailed on pages 37/38 of the manual.

If all else fails switch the power off for 10 minutes then restart the system.

Posted by: @editor

Is the message really that you need to contact a “competent” person. That’s really funny if it is. 

My Vaillant is the same, always makes me smile when I see that. The installer can fill in their own details on the system so it will tell you who to call; my installer didn't bother, possibly because even he didn't think he was competent 🤣

Posted by: @editor

My initial response in all issues with heat pumps is to check the filter and see if it’s restricting flow. I’ll pass your issue over to Vaillant tomorrow.

Is the message really that you need to contact a “competent” person. That’s really funny if it is. 

Tut Tut Editor, are you saying that the forum members are not competent? 🤣 

As I have been advising Junior Engineers for many years, 'If all else fails, read the instructions'. 😎 

@derek-m, if my heat pump had had the same great advice, my first port of call wouldn’t have been to call the local farmer every time we’ve had heat pump hiccups 😂

@squonk Snap and mine wasn't at all competent either

Sorted, found out its fault code F.788 - pump not running.  The controller manual fault section (left in my garage by the installer muppets) suggested switching it all off for 30 sec and restating it and its all fixed and we have a warm house.  I might have a career as a central heating engineer.  Thanks for the feedback everyone.

@derek-m Great advice, even better if the really thick install guides are left on site!

@witchcraft

You can always download the manuals, which is what I do. Just make certain that you have the correct one for your model.

The installers should have provided you with a handover pack, including the manuals, along with instruction of how to operate your system. Unfortunately it is quite often the case that this does not happen.

I am very pleased to hear that you have resolved your problem. Switch it off, count to ten and switch it back on, is a technique I have used extensively on industrial control systems. You would be surprised how many times it has resolved the problem. Sometimes the software just gets its knickers in a twist.

If the fault should appear again then check and clean any filters. Also check any plugs and sockets for loose connections.

@derek-m Handover pack, hmmm a handover of any sort would have been nice 🙂  Thankfully they left a full set of Vaillant docs along with the coke cans and general crap in my garage when they "finished".  I did get a compressed file of my room surveys, etc, too after I whinged about it.