Vaillant 418 ecotech plus mini explosion on startups

[BillD]

I`ve just had it installed in the kitchen . When there is a call for heat ,the gas on igniting creates a very disturbing mini explosion . It`s a shock as it is quite unexpected . The installer reckons this effect is standard on most boilers . Surely boiler engineering has advanced such as to overcome this problem . Multiple electrodes instead of just one !! I can imagine a cloud of gas , a lonely electrode at one end producing a spark ...........! Or is this
effect only on the Vaillant boilers . Any suggestions on minimizing this disturbing effect . Other than that the boiler works quietly and fine .

 

[mickyg]

doesnt sound correct, get it checked out. Did your installer check anything to investigate? What is the CO/CO2 and inlet working pressure measurement recorded as in the benchmark book?

 

[BillD]

Thankyou MickeyG . The co/co2 values are 0.0007 and when I called the installer back who did a tiny adjustment to the gas valve ..... ( made no apparent difference ) the second reading was 0.0005 . prs in mbar was 0.00 and 0.06 .

 

[mickyg]

that reading is irrelevant, the CO/CO2 value is what matters, needs checking high and low. Might be worth getting vaillant to look at it if the installer doesnt know what hes doing

 

[Dan Robinson]

Could well be under seized pipe work. I would be surprised if there was a problem with the ignition electrodes, but being a Vaillant.... it is worth checking.


Could a flue fault cause this? Nah...


One other thing worth checking..... did the installer remember to tighten the gas valve inlet test point screw? Have seen that before... boiler makes a definite pop/bang as not all hte build up of gas is expelled during the pre-purge cycle.

 

[gaswizzard]

I'm gonna take a bet the CO/CO2 is................

CO 40ppm/CO2 8%.

 

[BillD]

I took the advice and called Vaillant ,explained the problem ,a big Woooomph
on startup !! Engineer arrived the following morning , and established ,after numerous tests that the burner appeared to be the culprit . He ordered a replacement and the Reading based engineer fitted it a couple of days later .
It`s as quiet as a mouse ,both on startup and running . It`s brilliant . Thank you all for your assistance it was much appreciated .

 

[Agile]

The installer should have identified there was a problem and engaged the makers to deal.

I would love to know what the problem really was!

Tony

 

[BillD]

Tony the installer commented originally that all boilers behave like that on startups In blissfull ignorance one is often prepared to accept this as gospel ,so you put up with it . The Vaillant guy said immediately that there was a fault and no way should it make a WHOOOOOOMP on startups. The replacement part was the size of a baked beans tin with holes around the outside . A seal was also replaced . Hope this satisfies
your curiosity Tony .

 

[mickyg]

in 3 yrs working for vaillant i never replaced a single faulty burner ! you must be unlucky. Its a very reliable boiler generally.

 

[BillD]

Micky there may well be lots of people out there who are led to believe that a WHOOOOMP on startups IS the norm . Were they to complain , it is possible more burners would be identified as being the culprit !!!!!!!
You are as good a judge as any with your Vaillant experience ,so I`ll doff my hat to you .

 

[Agile]

Nice to know thats what was changed.

As Micky says its very unusual and still difficult for me to guess what was actually wrong with it.

Tony

 

[Bunnyman]

I've never changed one either on any Eco model. I'm with u agile what was really wrong?

 

[gaswizzard]

Had the burner loose on the door but this was a few years old , maybe it came out the box like this who knows , never had a problem with the burner on any vaillant.

 

[Dan Robinson]

That was my guess - would be surprised if was genuinely the burner. Can't think why a Vaillant Engineer would cover for a dopey installer though