Vaillant Fault F28 29 54, Resistance gas valve readings. 22vdc 16vdc. How to diagnose Vaillant fault

Has your Vaillant boiler stopped working and the display now say "F28 or F29 F54"
In this video I show you how to diagnose the boiler.
Also what might be causing the problem.
This video is aimed to gas engineers and trainee engineers under direct supervision.

[@Patent247]

Hello mate, had this exact same fault sequence. Changed the gas valve & all good for a couple of months, then started throwing the same faults again but managed to clear it and all good at the mo. 🤞. Seems to be common problem on these... Pcb next or scrapping tbh 😂

[@MHKBuildingSolutions]

I would say buy a refurbished PCB from eBay and change it if it gives you the fault again. These are very reliable boilers so worth keeping tbh.

[@cfgman1]

Probably the most comprehensive explanation I gave come across as you deal with both gas and electric issues...well done.
Keep up the standard
This fault was due to the gas valve and is a known design fault on the vaillants pros and plus which was kept quiet for many years.

[@MHKBuildingSolutions]

@@cfgman1 Thanks for your kind comments.

[@Razz60]

Very good video thank you for taking time for helpful video

[@MHKBuildingSolutions]

Thanks a lot.

[@Razz60]

@@MHKBuildingSolutions i think you shjd set up a training centre in the future because the way you explain things is very good we need more people like you in teaching

[@MHKBuildingSolutions]

@@Razz60 I am glad that the information is being received positively and helping others. Thanks for your kind words.

[@MrLibbyloulou]

Good learning video......wouldv'e like to see you doing your FGA tests....

[@MHKBuildingSolutions]

Thanks mate. Please don't forget to like and subscribe

[@zali1457]

Nice one mate 👍

[@MHKBuildingSolutions]

Thanks for the visit