Vulan Powerhouse needs new Controller Board and Gas Valve

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• Plumbers Quote Request #214241

Mark requested 2 quotes from Plumbers in Bayswater

  Easy access and illuminated roof mounted Vulcan PowerHouse 100 ducted heating system.
Fault: Unit does not always ignite.

The System generally fails to start. Eventually through several retries using the reset button on the RC handset it will eventually fire up and heat the house to the required temperature at which point the RC handset tells it to turn off. When the house temperature drops the system attempts to re-ignite at which point the system may or may not start.

I was able to to some diagnosis of the heater.

When starting this is what happens:
Comb Fan spins. Ok
Pressue Light Comes on Ok
Hot Surface Ignitor then glows brightly. (visible through side window)
Gas Valve Relay LED comes on.
1 to 2 seconds of time pass then any 1 of 3 scenarios might occur in any order.

Scenario 1.
Gas Ignites, Nice blue flame.
Flame detect light - Status Ok
Room fan starts - System works just fine.
However, Flame sometimes goes out after several minutes. (Low Gas pressure or valve fault?)
System retries but usually fails with Scenario 2 or 3 below.

Scenario 2 (Most common)
Gas takes longer to Ignite (approx 3 secs after gas valve relay LED lights) A nice blue flame for 1/2 seocnd with Flame detect light showing - Status Ok
Flame suddently goes out after 1/2 a second of igniting
Comb Fan stops
Diag light flashes Ignition Failure (7 flashes).


It seems that even when the gas has ignited, it has done so too late and the system treats it as an ignition fail and cuts the gas.


Scenario 3.
Hot surface is a nice bright orange.
However, gas doesn't ignite or maybe no gas in jets??
Flame Detect Light - Status No Flame.
Comb Fan stops.
Diag light flashes Ignition Failure (7 flashes).

I am tipping the problem is the Main electronic Gas Valve, The Gas Valve Relay (new pcb needed) or Gas feed pressure.

History of system:
To May 2009 system was trouble free.
In May system had 100% failure. We had a new hot surface ignitor fitted. The old one had fractured.
Since then, starting the system has become troublesome.


I am not a gas engineer so I cannot measure the pressures either side of the valve to determine if the valve is intermittant or defective. I am prepared to pay for a definitive diagnosis and repair as a replacement system could be expensive.

Parts info:
Heater is a Vulcan Power House 100.
estimate of age is 15 Years old

Main Circuit Board is a VULCAN H.S.I. Controller-N2
Part No 9241 2