Reznor Unit Heater Won't Light
 

I have a REznor unit heater that won't ignite in my garage.

I changed the diaphram and the venter motor. The venter motor was shot, the old one didn't turn on at all.

But it still doesn't ignite. The green light in the board blinks non stop calling for heat and the starts blinking twice.

WHat else could it be?

Reznor
 

Fan comes on?
Tries to lite? Can you hear it ticking?
Does it lite at all?

not familier with that heater,but most gas units sequence of operation start with call for heat,combustion blower starts,pressure switch proves ,pilot(or )ignitor)fires ,proves pilot,main flame ignition.Because you have a led light blinking twice ,that is a code for a problem I would say,check the manual for what that indicates.These are somewhat general instructions so good luck.if you post the model # I can look the manual and get a better idea what kind of heater it is.

I have a regular furnace in the garage that I had problems lighting for the first time. I had never had it going since I had bought the place.

First problem was that there was a second valve in the house that I didn't know about. Once I had found that, the second problem was that there was air in the line from the house all the way to the garage that needed to be purged out. Once that was accomplished, it ran fine.

Hope this helps.

Two lights means pressure switch didn't prove. It never clicks.


If it isn't the venter motor or pressure switch, I don't know what it could be?

:thinking-006:

the pressure switch connected to combustion blower by 2 hoses ,am i correct for your model,make sure hoses are on correct location,check the little nipple the hose slips on ,these things get plugged with deposits and won,t let pressure switch get the vacuum it needs.suck and blow on the hose as well and get the pressure switch to operate,sometimes they get sticky from sitting over the summer

I will try all these, but this is getting frustrating

Thanks

you can put a jumper wire on the 2 wires on the pressure switch to prove to yourself that this IS the issue.THIS IS ONLY FOR TROUBLE SHOOTING do not leave it there to fix the problem,you are bypassing a safety device.And then you figure out why it isn,t working or use a voltmeter to check for 24volts to ground on both sides of the switch.

Success.

It was a build up in the nipple, my guess saw dust.

Thanks!

Right on.that one can be hard to find sometimes.:angry3:

If you're making dust in your garage, make a habit of blasting out your heater with compressed air frequently, this is the cause of many a garage fire. I used to have to go and clean out heaters at a truss plant a few times a year as part of their insurance requirements. Shops with lots of woodworking should have dust extraction systems. Having heaters that have their own combustion air piped in prevents igniting dust from the air in the burner/heat exchanger. The exterior of the heat exchanger however, still needs blowdowns.

In most shops where sawdust is an issue I recommend hot water unit heaters, as then there's no combustion taking place in the affected area to ignite anything in the first place. The boiler room would be sealed off from these airspaces.

OK, here we go again for the 2013 edition of my flipping Reznor! Honestly, I think this is four years in a row I have had to service something to start the season, and it is 12 years old.


Anyway, it calls for heat............the green light flashes and then starts blinking twice. Not a sound.....not a tick, nothing. The venter motor (that is less than a year old) does not start.

What else could it be other than the venter motor?

Now, late this winter the cap on my exhaust pipe blew off in a storm. I didn't notice that until after the melt when I saw it on the ground. So very possible that water came in through the pipe.

Thoughts????

When I was much younger I used to get sawdust build-up in my nipples, but now I don't get as much wood and the issue has resolved itself.:)

I also fight yearly with an old Reznor. in my Mother-in-laws garage.It is frustrating

I am looking for a new heater for my shop. Is this a Reznor problem? Or common with garage heaters.

Perhaps its time to consider some professional help.... :thinking-006:

Sometimes environmental issues such as high humidity or chemical vapors can deteriorate things. I had some drain acid containers leak into the secondary containment tub I had them stored in and it rusted the living heck out of lots of stuff in my garden shed. Often times (as I noted in this same thread, but last year) ducting combustion air directly into the unit can alleviate lots of issues. I've seen condensation build-up in pressure sensor tubing cause havoc.

But, I'm not ready to quit.....................

But the venter motor doesn't start. So can I not narrow it down to the venter motor or the motherboard?

You could check the venter motor by disconnecting the leads to it and powering it directly with some jumpers. Whenever doing such testing be sure to isolate the gas supply. A person can function check a unit component by component, but many things have to happen in a specific sequence so they often cannot simply be jumpered out. I don't want to go into excessive detail on it simply because if I inadvertently omit a detail that's second nature to me, you could easily miss it and the consequences could be bad. When I need a dentist's services I go to one. When someone else needs a licensed, trained journeyman gasfitter they should consider the same.

I've found a number of those units where the fault was actually just a poor connection at a molex connector (multi-pin connection to the motherboard), sometimes at other spots. Sometimes its a bad ground. Etc, etc.