Repair Man Log Book.

[kevyluvu]

Hello,

I started this thread to post my repair jobs as I get them to give insight as to my thought process when I get a call. Some weeks I get no calls and some times I get 3-4 in a single day. I'm going to focus on the more complex calls in hopes that it might help a DIYer.

-Kevin

[kevyluvu]

Only heater I could not fix

I'll start with the only heater I could not fix.

A guy bought a brand new 2200 and after running it for only 2 weeks he brought the heater into the shop and said it kept cutting out on him. First thought was maybe he got a lemon, a monitor with a bad board etc. I always plug the monitor in and check the buttons to make sure they all work. I took off the grill and opened the pot door to take a look at the combustion ring and the flame detector.

I'd say about 50% of my calls have something to do with the flame detector. Sometimes the heater gets an ice dam and the heater runs horrible for a day or so until the ice melts or the heater is put on inside air, but during that time the heaters air intake is blocked starving the combustion process of air and the heater creates enough soot around the flame detector to connect to the side of the pot or the combustion ring and ground it. With a grounded flame detector the heater will never get past that safety and go to high. For the first few times the heater is restarted it will burn on low and the flame will go out in a couple minutes and the display flashes 88:88. If the heater is restarted 3,4,5 times there is a chance the initial starting will create enough heat for the main fan to turn on, but no progress is made because the flame detector is still grounding out.

Enough about flame detectors. The pot looked good, the flame detector looked good; everything looked great, like a brand new heater which it was. For good measure I stuck my ramrod wire down the fuel nozzle that feeds into the pot in case something was lodged blocking fuel flow, nothing. I put everything back together and took it over to our test bench and hooked it up to the fuel and started it up. It ran like a champ and had a nice blue flame all around the combustion ring on both low and high. The fact that the heater went to high tells me that it got past all the safeties and everything is working fine. My only thought at this point was that something was wrong at the location the heater was normally running.

After telling the owner I could not locate any problem I took the heater back to the guys garage and reinstalled it. He had a brand new tank with a clear goldenrod fuel filter. No water contamination, no ice blockage or any other foreign matter in the intake or exhaust. After hooking up the fuel and hitting the float switch I started it up and waited till the heater went to high. It did and I left not knowing why the heater was cutting out.

Maybe the heater had a microscopic hair of soot that clung to the pot wall and only grounded out when it went to high and the airflow going through the pot increased enough to make it raise up to touch the flame detector and ground out? Maybe the intake or exhaust got clogged and kept clearing itself? Maybe the wind kicked up and blew exhaust back into the air intake making the heater try to burn oxygen starved air?

Over the next few weeks the heater keeps going out and neither of us know why. I took a trip over to his house and took a look at the exhaust, and sure enough it had a partial ice damn. Snow would blow onto the top of the exhaust and sit there until the heater kicked on. The building the heater was in was pretty air tight so maybe the heater only turned onto low and warmed up just enough to trip the thermostat, and melt some of the snow that was sitting on the top of the exterior exhaust. Some of the snowmelt would freeze inside the air intake before it could hit the ground. Solution: Use inside air and plug the hole the hose came off with a cap. If you burn outside air in your heater it's more efficient because the air you take from outside is heater up and spit back out. If you take inside air to burn the efficiency goes down because you are using air that has already been heated to throw into your heater and spit it out the exhaust. Inevitably that air will be replaced by colder outside air since no house is completely air tight. Well the owner was a bit finicky and did not like the drop in efficiency, so he hooked it back up to outside air. The heater started cutting out again, duh. Well, maybe not... He said there was no ice damn. He did me a big favor a few days prior by letting me use a vehicle hoist inside his garage to change my block heater that went out on my diesel truck, so I wanted to return the favor. I told him he could use my heater which was the same model and had only 100 hours or so on it since I bought it for a shop I had just built. I told him I would install it in my house in place of my 441 so I could live with it for a few days thinking I might hear or see something to help solve the puzzle. I also did this to eliminate the heater as the problem. If my cuts out the same way his did the chances are very high that the problem is not the heater, but something else. Sure enough 3 days later he said my heater was cutting out. So what is it??? Well I know he has good fuel, a clean unclogged filter, good intake and exhaust etc. What I don’t know… Does he have good power, or is it cutting out turning the heater off? Well this is not an issue because when the power comes back on the monitor will turn back on to the default temperature. The heater was working well on inside air so the only thing left is the wind and how it is affecting the heater. My best guess is the wind is blowing in such a way as to push the exhaust gases back into the intake and the oxygen deprived air makes the flame go out. If this happens when the heater is on low the combustion ring is not glowing red, so when the wind changes direction to let the intake bring in good air the pot cannot reignite itself. Some days we get 40-50mph sustained wind speeds up here in Nome. The other day it was negative 35 with the wind chill. The advice I gave was for him to run inside air or build a wind diverter.

-Kevin

[pushkins]

I'm not sure this is the place for a "blog"

[Vinnymeyer]

I'm not sure this is the place for a "blog"

Maybe not, but I found the entry on troubleshooting that service call helpful. I'm currently troubleshooting a rather annoying Monitor 41, and every little bit helps.

[HayZee518]

anything having to do with monitor heaters should be in the monitor section of the HVAC heading. the first posters reference to "inside" air is dangerous because of the potential of blow back of combusted kero and air into the heated space. the heater was designed to use outside air as the combustion air and the exhaust blows outside. that was his first mistake. he failed to indicate if he was using the damper rings on the combustion blower's intake. the standard ring is used when the exhaust tube just goes through the wall without any extension piping. anything greater than 30 inches you don't need a ring.

[kevyluvu]

the first posters reference to "inside" air is dangerous because of the potential of blow back of combusted kero and air into the heated space.

Not dangerous at all. The fact is this can happen with inside air or outside air. Using inside air does not affect how the units exhaust the burnt gases. I did hear of a guy who told me the plenom plugged up with soot so bad that it restricted the air flow to such a degree that the heater build up pressure with the hot burnt gasses and finally blew out a bunch of soot as well as expanding the heat exchanger plenom so much that the weld gave way and each time after that the heater put a little bit of exhaust air into the living space which is not good. The plenom was replaced and problem solved. Anyone using any of these units toyo or monitor should have carbon monoxide detectors nearby in working order.

the heater was designed to use outside air as the combustion air and the exhaust blows outside. that was his first mistake.

This was not a mistake at all. Using outside air vs inside air has very little to do with anything except efficiency. In Nome where we have over 4,000 units in operation we have environmental factors that dictate the type of combustion air we use. These include ground blizzards of 40-50 mph blowing snow drifts against the house over the intake/exhaust pipes etc. Last winter the low was negative 36, and when it gets that cold and you only have one heat source you need it to work. In this environment some heaters develope ice dams on the air intake, and will not run. This is a prime example of why we use inside air. When the cold temps go away some people revert the heater back to outside air, but some leave it on inside air indefinitly.

he failed to indicate if he was using the damper rings on the combustion blower's intake. the standard ring is used when the exhaust tube just goes through the wall without any extension piping. anything greater than 30 inches you don't need a ring.

It was a stock install with no extension kit so the stock ring cap was used. This also has very little to do with the problem discussed above because whenever I cannot find an obvious problem visual/audible/smell I take my manometer to measure and set the proper airflow between the top and the bottom of the pot to factory specs to get the most efficient blue flame burn.

I know you help a lot of people in here HayZee and I thank you.

-Kevin

[hawkins111]

frosted flue pipe

We are into our second week of -25 weather with 80% humidity. I have had calls from at least 10 Monitor heater owners that have had their flue pipe frosted over. With this kind of weather you have to look at the flue pipe every two hours or so. For those that can’t get back to their house the only thing to do is disconnect the air hose inside the house. We have been lucky because there has been no wind. Once the weather warms up some they can put the air hose back on. This happens a couple of times each winter. I can not tell how many people just disconnect without being told as this happens to them every winter.


Stay warm, Tom
Bethel, Alaska