# Forum Home Renovation Heating & Cooling  Brivis Buffalo 85 Problem

## Chexfxdx

Hi all, 
I have a Brivis Buffalo 85 ducted heating system which has a problem, after a lot of searching and reading numerous posts I believe the problem is the Thermocouple. Now, I have found a generic Thermocouple which is suppose to fit but I am a bit reluctant to "rip into it" pulling the heater apart and I was wondering if there was an easy way to get to and remove the Thermocouple?   :Confused:  
Any help is greatly appreciated.  :2thumbsup:  
Cheers,
Glenn

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## ozheat

Turn power off to the heater.  Turn gas off to the heater.
Remove thermocouple nut and pilot tube nut from regulator.
At the burner there are 2 screws that hold the pilot assembly, remove them and wiggle out the assembly.  Do not bend or kink the pilot tube.  Also there may be a wind deflector that you need to remove aswell.
With the pilot assembly removed you can see the screw holding the thermocouple.  Note how far the themocouple protudes out and then replace themocouple.
Replace pilot assembly at the burner.  This process is pretty difficult to get back in and don't cut yourself on the burners.
Replace pilot tube and thermocouple at the regulator, do not use any teflon or thread sealant on threads and DO NOT cross thread the nuts or you will have to replace the regulator. 
I would also recommend taking a photo of the pilot assembly and regulator prior to taking them apart because by time you get to putting it all together again you may have forgotten how they went

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## jaury

Hi Glenn, 
What sort of problem does your buffalo have? And how do you know if the problem is the thermocouple?
I also have a problem with my Buffalo 85, where the fan is not working, any idea? 
cheers,
jaury

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## chrisp

> Turn power off to the heater.  Turn gas off to the heater.
> Remove thermocouple nut and pilot tube nut from regulator.
> At the burner there are 2 screws that hold the pilot assembly, remove them and wiggle out the assembly.  Do not bend or kink the pilot tube.  Also there may be a wind deflector that you need to remove aswell.
> With the pilot assembly removed you can see the screw holding the thermocouple.  Note how far the themocouple protudes out and then replace themocouple.
> Replace pilot assembly at the burner.  This process is pretty difficult to get back in and don't cut yourself on the burners.
> Replace pilot tube and thermocouple at the regulator, do not use any teflon or thread sealant on threads and DO NOT cross thread the nuts or you will have to replace the regulator. 
> I would also recommend taking a photo of the pilot assembly and regulator prior to taking them apart because by time you get to putting it all together again you may have forgotten how they went

  It is great to see this type of helpful and detailed response. 
Well done, ozheat!   :2thumbsup:

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## Chexfxdx

> Turn power off to the heater.  Turn gas off to the heater.
> Remove thermocouple nut and pilot tube nut from regulator.
> At the burner there are 2 screws that hold the pilot assembly, remove them and wiggle out the assembly.  Do not bend or kink the pilot tube.  Also there may be a wind deflector that you need to remove aswell.
> With the pilot assembly removed you can see the screw holding the thermocouple.  Note how far the themocouple protudes out and then replace themocouple.
> Replace pilot assembly at the burner.  This process is pretty difficult to get back in and don't cut yourself on the burners.
> Replace pilot tube and thermocouple at the regulator, do not use any teflon or thread sealant on threads and DO NOT cross thread the nuts or you will have to replace the regulator. 
> I would also recommend taking a photo of the pilot assembly and regulator prior to taking them apart because by time you get to putting it all together again you may have forgotten how they went

  Hi ozheat, 
Thank you VERY much for your assistance, I followed your instructions and found the Thermocouple was easier to remove than I first thought, I envisaged having to remove a lot more than was actually necessary. After turning off the gas and electricity, I used a pipe spanner (3/8 and 7/16) to undo the thermocouple nut (and tube) as well as the pilot light nut (and tube), I then searched for the two screws you mentioned but my choices were the three screws which held in the Burner assembly or a single screw which was located on the top of the pilot light assembly, once I loosened this single screw (I didn't remove it entirely) the pilot light assembly slide towards me and after leaning this assembly over to the left, it slide straight out. After disconnecting the wire for the ignitor, the whole assembly was free from the heater unit. 
Photos were taken before disassembly and now that I know how it comes apart it should be a cinch to put it back together once I get a new thermocouple. Also after reading numerous threads, I will pay particular attention to NOT cross-threading the (pilot tube and thermocouple) nuts. 
Thank you once again for your excellent advice  :2thumbsup:  
Cheers,
Glenn

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## Chexfxdx

> Hi Glenn, 
> What sort of problem does your buffalo have? And how do you know if the problem is the thermocouple?
> I also have a problem with my Buffalo 85, where the fan is not working, any idea? 
> cheers,
> jaury

  Hi jaury, 
Initially there was only cold air pumping out of the floor ducts, I went out to the external heater box and lifted the lid, I noticed the pilot light was out and when I followed the re-ignition procedure, the pilot light would only stay lit while I held the button down, once I released the button on the gas regulator the pilot light would go out, no matter how long I held it for. 
As for your fan problem, I'm sorry but I'm not real sure what it could be, best idea is to do a search on this forum for "Buffalo 85" and do some reading, if this doesn't bring you an answer the next step would be to post a message about your heater problem and I reckon someone with a lot more experience than me will be able help you out. But the search engine is the best first step.  :Smilie:  
Cheers,
Glenn

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## Chexfxdx

Well... after buying a 600mm universal Thermocouple (part #082801) from Tradelink, and 5 minutes in front of the heater, it is all finally up and running beautifully.  :Happydance2:  
The total cost of fixing the Buffalo 85 was $27, I reckon this forum has saved me at least $130, so a BIG thank you once again to ozheat  :Clapping:  
Cheers,
Glenn

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## jaury

> Hi jaury, 
> Initially there was only cold air pumping out of the floor ducts, I went out to the external heater box and lifted the lid, I noticed the pilot light was out and when I followed the re-ignition procedure, the pilot light would only stay lit while I held the button down, once I released the button on the gas regulator the pilot light would go out, no matter how long I held it for. 
> As for your fan problem, I'm sorry but I'm not real sure what it could be, best idea is to do a search on this forum for "Buffalo 85" and do some reading, if this doesn't bring you an answer the next step would be to post a message about your heater problem and I reckon someone with a lot more experience than me will be able help you out. But the search engine is the best first step.  
> Cheers,
> Glenn

  
Just want to update on my Brivis Buffalo 85 problem, it is now fixed. Thanks Glenn, the research was really worth it. 
The problem was a faulty current limiting resistor to the zero crossing detector circuit (connected to four diodes and 4n35 optocoupler). 
The symptom was after turn on the power to the heater, the burner will start but then after a little while it will stop due to overheating because the fan was not working. All the LEDs on the controller board were turn on, solid. Checked the thermostat, the sensors and the fan motor, all working fine. So the problem must be on the controller. 
I was motivated by the post from chrisp (http://www.renovateforum.com/f193/he...-repair-96444/). Thanks chrisp for a very detail post. 
So I decided to open and check the controller PCB (I think mine was a Tek321 controller) and found the faulty resistor (the physical appearance was still looking good but measuring it using DMM indicated otherwise)  :No: . 
Replaced the resistor and put everything back, and now the house is warm again  :happy: 
The cost........one resistor  :Yes: . 
cheers,
jaury

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## Chexfxdx

> Just want to update on my Brivis Buffalo 85 problem, it is now fixed. Thanks Glenn, the research was really worth it. 
> <message snipped> 
> Replaced the resistor and put everything back, and now the house is warm again 
> The cost........one resistor . 
> cheers,
> jaury

  Hi Jaury, 
I'm glad to hear you got the problem solved and the fix was an inexpensive component, no doubt if you had called out a repair service it would have meant a replacement board or controller and not only is that an expensive proposition but also a waste of a good piece of electronics. I sometimes wonder if the repairer don't actually take the board back to work and replace the faulty component and then sell them as a new board to the next sucker... umm... victim...errr... customer  :Biggrin:  
Cheers,
Glenn

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## NAL

Hi Guys 
Please help I need your advice -  I have a Brivis Buffalo 85 and from the info I have (bought the house recently) the unit was probably installed in 1995. 
I replaced a faulty thermocouple as the pilot light was not staying on so now the pilot light is working fine, the burners are working, I can hear the fan working and good heat is coming out of the exhaust but the air from the vents are coming out lukewarm and cooler in the rooms far away from the heating unit.  The passage where the return air is located is working fine and the internal controller is a manual type and the internal setting is set on .(point) 2 as printed on the outside unit. Please advise why air in the house is coming lukewarm/cold 
Thanks  
NAL

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## Godzilla73

G'day, 
Get it checked for a cracked heat exchanger, this is also a health hazard. I'd also check your duct work, be it in the roof or under the floor for holes or loose connections. Duct tape has a habit of drying out and coming loose.

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## plum

I'd be checking the duct work first, dogs or cats, if they get underneath will stuff them up in no time. Also check your return air filter behind the grille, they get clagged up with dust.

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## justinT

> Just want to update on my Brivis Buffalo 85 problem, it is now fixed. Thanks Glenn, the research was really worth it. 
> The problem was a faulty current limiting resistor to the zero crossing detector circuit (connected to four diodes and 4n35 optocoupler). 
> The symptom was after turn on the power to the heater, the burner will start but then after a little while it will stop due to overheating because the fan was not working. All the LEDs on the controller board were turn on, solid. Checked the thermostat, the sensors and the fan motor, all working fine. So the problem must be on the controller. 
> I was motivated by the post from chrisp (http://www.renovateforum.com/f193/he...-repair-96444/). Thanks chrisp for a very detail post. 
> So I decided to open and check the controller PCB (I think mine was a Tek321 controller) and found the faulty resistor (the physical appearance was still looking good but measuring it using DMM indicated otherwise) . 
> Replaced the resistor and put everything back, and now the house is warm again 
> The cost........one resistor . 
> cheers,
> jaury

  I live in Melbourne (highett) and have a Brivis Buffalo 85 central heater which is experiencing the same issues that you described in this post. The pilot light is on and when you turn the system on it fires up but the fan doesnt turn on. After a minute or so the system turns itself off (because the fan isnt on to advoid over heating). I have called up a couple of heating companies and ihave been told that it will be over $200 just to get someone to look at it, before parts (was told the part could cost up to $500)! We are looking to renovate later this year where we will likely upgrade our central heating unit so dont want to spend too much money fixing the unit as it would probably be cheaper to get a new one! 
I only have basic skills when it comes to fixing something like this (limited understanding of electrics), so was wondering if you could describe how i access the controller and diagnose the issue to fix it? 
Thanks for your help, 
justin

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## plum

It may not be the tek box. Sometimes if the flame from the burner licks out the front it will shutdown, indicating a fault with the heat exchange. Or the fan may of burnt out. The first and easiest thing to check first is the return air filter, located behind the grille, make sure it's clean.

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## justinT

> It may not be the tek box. Sometimes if the flame from the burner licks out the front it will shutdown, indicating a fault with the heat exchange. Or the fan may of burnt out. The first and easiest thing to check first is the return air filter, located behind the grille, make sure it's clean.

  Thanks Plum, I checked the return air filter but our system doesn't have a filter (it's located in the bottom of a cupboard in the hallway). I spoke with the guy at gasstop yesterday and he didn't think it was the controller either... Most likely an issue with the fan?

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## MiltonT

> Thanks Plum, I checked the return air filter but our system doesn't have a filter (it's located in the bottom of a cupboard in the hallway). I spoke with the guy at gasstop yesterday and he didn't think it was the controller either... Most likely an issue with the fan?

  The fan will not run if the capacitor is faulty. To replace it you must ask for a motor run capacitor, not a motor start capacitor. It is 15 microFarads (uF) capacity. Mine recently failed. It tested at 12 uF. It was 18 years old. This is the most common cause of tangential fan failure; actual motor failures are much rarer. Middendorps can probably supply a replacement for about $15 but they do not have test facilities. BE VERY CAREFUL HANDLING THE OLD ONE. YOU CAN GET A SEVERE, POTENTIALLY FATAL ELECTRIC SHOCK. DISCHARGE IT FULLY BEFORE REMOVING IT. You can find how to do this on the web. When you install the new one it may take several attempts at starting the motor before the capacitor is conditioned. I did this last month and have never looked back. 
Cheers

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## sundancewfs

> Well... after buying a 600mm universal Thermocouple (part #082801) from Tradelink, and 5 minutes in front of the heater, it is all finally up and running beautifully.  
> The total cost of fixing the Buffalo 85 was $27, I reckon this forum has saved me at least $130, so a BIG thank you once again to ozheat  
> Cheers,
> Glenn

  Love this site!
Same problem, same model, same solution. All fixed and running! :2thumbsup:  
Mind you the part number I got from Tradelink is different. I was told they had been having some issues with part#082801. Mine was: item code 13067260 Thermocouple uni 600mm NG S.I.T. brand. Total including GST $23.42

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## Matt88

Thanks for the info on this thread - got to love the internet. I have just removed the thermocouple from my Brivis Buffalo 85 unit and will send the wife down to Reece tomorrow (Monday) to get a replacement (if she doesn't want to go and get it she will have to wait until Saturday for me to buy one). 
I had this replaced one other time and it only cost me $77 for a tradie to do it back in 2005 which was a damn reasonable price. 
Here's some pictures of the unit before taking out the thermocouple.

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## plum

I'd be crossing my fingers that it is only a thermo-couple. Does it looked burnt out or dis-figured at the tip? If not, there is still a gas control and tek box to consider. Good luck.

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## Matt88

> I'd be crossing my fingers that it is only a thermo-couple. Does it looked burnt out or dis-figured at the tip? If not, there is still a gas control and tek box to consider. Good luck.

  It looks pretty much burnt out. If I get a chance I'll put a side by side photo tomorrow with the old and new.

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## Matt88

All done - working fine. Only took a few minutes. Part was $37 from Reece.  
Here is a picture of the old and the new thermocouple.

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## watson

Well Done Matt88  :2thumbsup:

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## Camo1975

Hi have a problem which would be much appreciated if anyone has any input.
 When l turn on inside thermostat fan on unit starts up and pilot is on but machine does not try and ignite burners so only cold air comes out of registers
no red lights on PC board seem to come on and only replaced Pc board last winter with a new one.
were to now 
doesn't seem that any gas is even reaching burners not sure system procedures
anyone

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## Chexfxdx

> Hi have a problem which would be much appreciated if anyone has any input.
>  When l turn on inside thermostat fan on unit starts up and pilot is on but machine does not try and ignite burners so only cold air comes out of registers
> no red lights on PC board seem to come on and only replaced Pc board last winter with a new one.
> were to now 
> doesn't seem that any gas is even reaching burners not sure system procedures
> anyone

  Hi Camo1975, 
If your pilot light (flame) is working then it is a different problem to what I encountered back at the beginning of this thread (and the reason I am re-reading this thread is because it looks like my thermocouple is "cactus" AGAIN  :Annoyed:  , I'll have to see about the NEW replacement part which sundancewfs mentioned), so sadly I am unable to help, hopefully someone else can step up to the plate and suggest what you can look at next... 
Cheers,
Glenn

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## petesteele

Hi, 
I noticed the other day that my Buffalo 85 has a soft hum when it is plugged in, but not running.  I didn't think this was a problem however I checked with a power usage meter and found that it draws 20 watt.   
I was wondering whether other people think this is normal or if I should investigate further.  20W is not much but but when running constantly it adds up. 
Thoughts? 
Thanks,
Pete

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## xfile

After reading this forum on various posts on the Brivis Buffalo 85 I was able to fix the heater myslef ...learn a little and save a few bucks along the way  :Smilie:  My problem started when the heater would start up and then click on and off and eventually just blowing cool air and would not shut off unless I turned off the power to the unit outside.  
I worked out that the thermocouple was o.k because the pilot remained on. I knew the fan was o.k because it was blowing cold air. I knew the wall thermostat was o.k because it turned the outside unit on so it had to be the Tek-board or the gas valve. 
I switched off the gas main and turned off the power and removed the Tek-board ( easy job ). I found that the board had fried a few resistors etc ....anyway I shopped around and found a change over for $204.75 from Module Repair Service 
I tested the gas valve and found that one of the terminals was not connecting properly ( corrosion ) so I decided to replace it as it would give out soon enough. I picked one up from Reece in Ringwood. 
Anyway, for those who have the original two pin Gas Valve and when they give you the replacement it's a 3 pin ...just remember to add the white wire to the first pin and connect it to the Tek-board as in the photo i attached otherwise your system will only blow cold air again and the main valve will not open. The order of the wires in color top down should be , white, orange, blue. 
I hope this helps someone as I learned heaps from reading all the various posts on the subject. 
Cheers, 
Mark

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## DaNavyKid

Mark and all others, 
Thanks for all of your problems, tips and repairs.  I have read through most all of the entries in this forum and cannot find anything completely describing this years Brivis Buffalo 85 symptoms.  My model looks exactly like Mark's with a different, but similar gas valve.  I have had issues in the past with flame roll-out, thermocouple, and weak pilot flame, all of which I have dealt with successfully.  The symptoms this year are:   Pilot Lit, No fault lights or abnormal indications.Switch thermostat on, unit starts as per normalThe unit produces heat, with flames all looking normal and blower functioning normally.If it is daytime and the temperature differential (thermostat setting vs house temp) is low, the unit will operate and maintain the house temp.  In this instance, the unit is usually on for less than 10 minutes.If it is morning and the temperature differential is high (night time thermostat setting of 17 vs daytime of 20), the unit will start as normal, however;After between 10 and 30 minutes of heating, the gas valve and pilot will trip off.Every time it trips, I have been unable to observe any error lights. 
I have read on this site about some possible problems, including return filter clogged (don't seem to have one and air flow on the return register is normal), cracked heat exchanger (unlikely due to inspection 2 years ago, and also problem occurred straight away with post summer startup), faulty tek board (unit runs normal all day without a problem, no visual abnormalities noted on board). 
I am wondering if it is the OH/F or OH/S sensors.  Do these sensors trip the gas valve?  Also, do these sensors latch in when activated?  I am thinking that maybe I need to set up camp one morning and watch the unit for 30 minutes to see if I can spot one of these LEDs light up momentarily. 
Any guidance or other ideas will be greatly appreciated.

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