Brivis Buffalo 85 Blowing Cold Air

Hi,
I have a Brivis Buffalo 85 Ducted heating system. The Pilot is lit & stays alight but when I turn the electonic thermostat on to fire up the unit, the main burner does not cut in & the fan blows cold air .
When I bridge out the terminals for the thermostat (R &W). the main gas valve clicks (or clunks) as if it is opening but still no main burner. I have made some enquires & I am getting conflicting info on whether this means the problem is the main gas valve or the main electonic unit in the system. Does anyone know what voltage should be across the terminals of the gas valve? (It is a 3 terminal gas valve not 2).
I read on another post that you can test the gas valve by using ohms with the power off, is this correct?
There appears to be a retard valve across the White & Blue terminals of the gas Valve unit. This has voltage up until I bridge the (R &W) terminals of the thermostat.
The gas valve itself, is across the blue & orange wires of the 3 terminals & I am getting voltage across these terminals when I bridge out the (R & W) terminals of the thermostat connection. I am therefore assuming that the electronic unit is sending the correct voltage to the gas valve but there is a fault in the gas valve unit itself.
Any advice appreciated

I have since replaced the gas valve with success! The unit was therefore sending the correct message to the gas valve from the thermostat & the main electronic unit within the heater. The gas valve has 2 solenoids, one to allow gas through & one to shut off the gas as a safety. (Or that is what I believe happens)
I presume one of them was faulty. I have learnt a fair bit from this repair, so if you have a similar problem, I may have the answer & am happy to help with advice.

Nice work jfm - there are a few here who should probably not play with gas or electricity for that matter but glad you had a positive outcome.

My brivis unit will not fire up (with indoor thermostat turned on - 20 degrees) unless the unit's fan is set to manual mode (fan runs continuously). If I change the fan to auto while the unit is fired up - it will keep running - but once turned off at night (from in the house) will not restart the following morning. If I go out in the morning and push the button to manual (pull button for auto) it fires up like normal. I do not think it is the switch as I can change from manual till auto while the unit is fired up and it keeps on working. HOW CAN I GET HOLD OF A WIRING DIAGRAM for this unit? I feel there must be some sort of safety interlock in auto fan operation that is faulty. Any help would be appreciated - Thanks!

So i take it your a registered plumber then ?

leave it to the experts.

Well said pattycake4 what people don't realise is playing around with gas appliances are a dangerous thing and what they don't seem to realise if something goes wrong with their gas appliance and the house burns down or even worse they kill a loved one in the house due to fire they will not be covered by insurance and will also be proscueted in the event of this happening .

Hi,

I have the same problem with my brivis buffalo 85. Pilot on, can't fire up the unit. I had an electrician friend tell me that electrics are fine. Brivis can't come out for another two weeks. I am just wondering if you could tell me more about how you changed the valve? Where you bought it from etc. Thanks in advance. Please call me if it's easier. Joe

I went parachuting once and it turned out very badly when my chute didnt open. As I plummetted to earth this guy came flying up from the ground, all charred and with his hair on fire
,Quick I said "do you know how to throw the emergency chute?
Sorry mate I dont, he said, but do you know how to change the gas valve on a buffalo 85?

Ours was blowing cold air too.. Turned out to be as simple as the pilot light had gone out.

Problem now is that when I follow the instructions to light it, as soon as I release my finger, it goes out. I've tried holding it down for we'll over a minute, but no good.

Anyone got any ideas why it's not staying alight?

Pilot light not staying lit is most often cause by the thermocouple. Thermocouples don't last forever and they do die over time.
They are a cheap and easy fix, just get yourself a plumber to install a new one.



Yep Gas valves do poop themselves, they aren't a common thing that dies, but they do.

And yeah leave all gas appliances to the experts. I am a registered Plumber, and i have the utmost respect for gas appliances. They can be VERY dangerous if you don't know what you are doing.

Thanks Frothy_monster! It was the thermocouple. Called the plumer now all fixed, thankfully with 3 young kids!