Central Boiler: The Good, the Bad and the Ugly

The Central Boiler Classic Edge 750 has some weak spots, and some good; here is the story so far

Dec 18, 2019

Based on the research done before purchase, and experience since, I think the efficiency of the Central Boiler Classic Edge 750 is top shelf. Best of the best, I don't know, but damn good. To heat our ~2,000 square foot home we burn about six full cords of hardwood firewood per heating season. The cost savings over propane are 2/3rds, and that's if we buy the firewood as opposed to putting it up ourselves. This year we are on track to provide all of our own firewood, which means no cash outlay. That's why we bought the outdoor wood boiler in the first place. I usually load it twice a day, once shortly after waking, and once after dinner. If I'm going to be absent I can load it up fully for at least a 24 hour burn. Big contributors to its efficiency in my opinion are the "reaction chamber," where the "wood gasification" burn takes place, and its ability to idle for long periods without consuming much fuel wood. Also, the Classic Edge has been reliable, which is to say that it runs when I need it to run.

The Bad: Central Boiler Classic Edge

The firebox door seal has been a niggling issue for quite some time. The problem is that once you have any sort of leak at all, smoke from the firebox escapes through the leak, and worse yet, creosote starts to build up. Of course the creosote worsens the leak, and you are off to the races. The seal is silicon and not easy to clean. The hinges are adjustable for seal pressure, as is the "cam latch," unfortunately I've not been able to stop the leaks. For example, if you want more pressure at the upper left you can do that, but then the lower right corner of the door wants to push out, creating a leak there. Admittedly I'm not a Central Boiler technician, it's highly likely I'm doing something wrong, but the door seal has been a pain in the ass. I'll limp through this heating season and replace the seal when I have more time on my hands; the part is on hand.

The Ugly: Central Boiler Classic Edge

Recently I began to get an intermittent "d.o." indication on the control panel, which stands for firebox "door open." I thought maybe I could live with this, but no, the switch is an input to the blower control, which is to say the outdoor wood boiler will not operate properly without an intact "door open" circuit. There is a small switch near the cam latch; I removed and checked the switch, it's working as designed. Called Central Boiler, they instructed me to have a look behind the control panel, which is accessed by removing to screws and loosing to screws on the hinge side.

Ugghhh, "Houston, we have a problem."

Why I’m So Bothered

Let me count the ways.

1) This product is intended to be outdoors, i.e. it is commonly referred to as an "outdoor wood boiler;"
2) it provides heat, which at least implies that it is intended to operate in the winter months; and
3) it is fired by wood, which leads me to believe that most Central Boiler wood-fired products find homes in rural or at least semi-rural settings. What else finds home in rural or semi-rural settings I ask? Mice!!! And lots of them. And in the winter months mice look for cosy little homes wherever they can find them, by coming into your house, finding a warm spot under the hood of your car or truck, under the engine cover of the Wood-Mizer, under the fuel tank on the wood splitter (another recent occurrence), or in your outdoor wood boiler. That space we are looking at in the picture above is maybe 3 inches deep with the door closed, a foot high more or less, and about 8 inches wide. The ENTIRE control system comes together in that space. If there is one place on the Central Boiler Classic Edge where you can't have a mouse infestation the space behind the control panel is it. You'd think it was rocket science. Central Boiler has been in business for over 35 years, they should have a library of protocols for preventing damage from mice.

Okay though, I get it, we're in business, too, and it's not perfection. Incidents such as these can actually improve customer satisfaction, IF you take care of the customer. Alas, no. It's not covered by warranty, and I can't even get my rep to answer the phone anymore. So indeed, I am presently an unhappy camper.

Note to Self: Settle Down and Move On

Okay self, let's talk about what needs to be done to rectify the situation. First up, some sort of temporary fix to get the Classic Edge back up and running. The first step I took was to clean up the mess as best I could with some brushes and the shop vac. The cause of the problem became readily apparent.

A pin in a connector within the door open wiring harness had been corroded away; hence the persistent "d.o." indication. Obviously this is the "presenting problem," the one you notice, which is not the same thing as the root cause problem, which is mouse infestation. But, we need to correct the presenting problem to get the Central Boiler back in action. The cost of propane is simply too high; I don't want to afford to wait until permanent corrective actions can be taken. All of the connectors in view are suspect though, which means that all harnesses going to and from the control panel and the various sensors and active components are suspect. More on that in a bit.

Yes, it's ugly I know, but it should get us through the season. I detached the panel through which the connectors pass, cut the wire on the other side of the connector, pulled it up past the connector and plate, and spliced it to the wire from the control panel. Cheap in every sense of the word, but effective. The interim solution only needs to carry us through 3 or 4 more months. Back in action.

Permanent Corrective Actions - Classic Edge Door Seal

The door seal is easy, relatively speaking; out with the old, in with the new. Classic Edge Firebox Door Seal Kit p/n 2500178. I could probably take this on during the heating season, if we get another little warm spell. I'm guessing I won't, but it's a possibility. [/av_textblock] [/av_one_half]

Permanent Corrective Actions - Classic Edge Control System

Frankly, I don't even like thinking about how much work this is going to be. At first glance it seems to me that the roof panel on the outdoor wood boiler will need to be removed, as will the front and the right side, as you are facing the machine.

The first two harnesses pictured, are both required to repair the "presenting problem" of the door open indication. The other two harnesses are suspect due to the damage caused by the mice, both their urine and their gnawing on wires.

There is a lot of work to do. Replacing the door seal, and replacing the entire set of wiring harnesses behind the control boxes and within the body of the boiler. And, since apparently Central Boiler hasn't done it, I will need to find a way to prevent future mouse infestations, especially, but not only, behind the control box, where all of the harnesses come together and are most susceptible to damage. When I get to that I intend to document the work here on the blog. The costs savings accruing to us through use of the Central Boiler Classic Edge 750 are significant, and therefore I will continue to fight the good fight, bulletproofing this machine myself if I have to, which evidently I do.