Hi,
My son & partner have just moved into a house with a Vaillant 3257 NG Internal HW system in the laundry. After noticing a smell of gas in the laundry occasionally, upon further investigation it appears that when using a certain hot-water tap that has low water flow (a newly-installed laundry tap with narrow piping!), the HW system “kicks in” and gas is emitted to the burner, but the burner does not ignite. This does not seem very safe – replacing the piping is probably the ultimate solution, but is/should there not be a mechanism in the system that shuts off the gas if the burner does not ignite?
The burner ignites ok when (all) other hot-water taps with higher water flow are opened.
Thanks for any advice.
Regards,
Peter.