over heating on new EKO 40

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Rembo

New Member
Feb 25, 2009
11
Glenside Pa.
Just installed a EKO 40 and am having overheating issues. Followed the piping diagram sent by cozy heat. I am using system with oil boiler also. Piping diagram didn't show installing aqua stat so we didn't. I have fired up the boiler twice first time set temp to 180 it overheated then set it to 170 again overheated. Called cozy heat they said the temp sensor was not damaged. I had knowledgeable conventional boiler guys do the install What are we missing. I don't have a dump zone.
 
When you say it's overheating, do you mean it's going into idle mode, or is the water temp shooting up past 200 degrees? The boiler is designed to go into idle mode when it hits the setpoint you specify on the controller. If you set it at 180, the blower will shut off at 180 and not come back on again until the water temp is around 175. That's not overheating--that's just normal operation.

If your boiler water temp is getting over 200 degrees, then either the blower isn't shutting off when it should (the max is 195), or your main pump isn't working or you're not putting the hot water into any radiant zones. That should be pretty easy to diagnose and fix.

I don't have a dump zone. I only overheated the boiler once in two seasons of operation due to a wiring problem that shut down the pump. I do have an aquastat on my return line that won't allow the main circulator pump to come on below 160. That's simply so that the boiler can get up to temp before you starting pumping water away from it. It's not strictly necessary, but it does make for better gasification earlier in the burning cycle. You should also have some sort of low return water temp protection plumbed into your boiler to protect it over the long term from corrosion, but that's something that can be added later and you won't hurt anything if you don't have it over the short haul.
 
The fan is turning off, the temps keep climbing till the e-2 code appears,(216* or so) circ pump is running and is hot. Since I am hooked into my oil boiler also which circ pump are you considering the main pump? How would you go about diagnosing? thanks
 
What is your oil boiler aquastat temperature setting at? Before I started burning wood, my oil boiler water temperature was set at 210 degrees. You may have your oil boiler turned off, but I figure I would mention it.
 
I hate to bring this up, but is it possible that the bypass damper is being left open? (this has happened to me)

There is no need with the new controller to use the aquastat to keep the pump off - you can specify the pump-on temp in the controller software. I did not end up usint the aquastat either.

If the damper is closed, then perhaps you have primary air settings too wide or too much draft, causing combustion in the top chamber when you don't want it. Either that, or as Eric said you are not removing the heat fast enough.

Hope we can help!
 
I'm with Medman on the bypass damper. Once the fan shuts off, the boiler should stop heating up, for sure. Are you pulling the bypass damper lever forward so that the wood gas is forced down through the nozzle? I agree that's not something you would normally think about if you're used to a conventional wood-fired boiler or not familiar with how a gasifier works. If you are pulling the lever forward, are you sure that the bypass damper is working properly, i.e., completely blocking off the exhaust outlet?

The "main pump" would be any circulator that moves hot water away from the EKO and into either another boiler vessel or your heating zones. If you have a pump doing that, the boiler temp should not continue to rise if the blower is shut down.
 
The circulator is running, but are you sure it's moving water? Do you have all the air out of the lines? Are you getting heat to the points of radiation in the system, ie baseboard, heat exchangers, etc?

cheers
 
I like the airlock theory, though you wouldn't think that pros would walk away from that.

If the boiler is reaching those temps, then it's pretty obvious that the boiler works. The problem is getting the heat distributed.
 
I had a similar problem when I first fired up this fall. I found that the air damper at the output of the fan was sticking open due to the center of the panel sagging in upon torquing the screws. I put a couple stand-offs near the center of the panel to keep it flat when tightening the screws and also applied about 40 grains of weight as measured on my powder scale on the damper counter balance. Huge improvement!
 
Re-bled all radiators they are 100%. Water temp on oil boiler was 220 I reset that to 140. Checked bypass on wood boiler its closing all the way. wood boiler temp is set for 150 and is currently reading 168. Checked aqua stat on oil boiler it is set at 180 and 160. Would I build heat in the wood boiler if the circ pump on the oil boiler wasn't working? water is moving to the rads. In the oil boiler aqua stat there is a third dial that says diff. that is set at 10 should it be set to 20 meaning the diff between the high and low 180 to 160? When I first fired up the wood boiler and gasification started the oil boiler started up and ran for quite a while???
 
I'd shut off the oil boiler for a day or so and see what happens. It almost sounds to me as though the OB is pulling most of the load, leaving the EKO with basically nothing to do.

I should add that bleeding your radiators won't solve an airlock in the piping. Finding and resolving airlocks can be tricky, but typically they occur at high points in the system where the water is heading down. It's important to install bleeders or connections at those points that you can open to let the trapped air out. The air gets trapped there and the water can't flow.

You'll know soon enough if that's your problem if you shut off the oil burner and rely on the wood for heat--because if you have an airlock, you won't get any flow; your boiler will overheat and your house will get cold.
 
If all my rads are hot is that an indication that I don't have an airlock? I'm turning off the ob now. Will that render my house themistat useless?
 
It depends on how it's plumbed, but if it's like mine (plumbed in series), if you shut off the burner but the zone pumps stay on, then the stats in your house will still start the pumps and keep the house warm. All the wood boiler does is put hot water into the (in my case) gas boiler for distribution into the house. I'm guessing that's how it's set up, unless you have a separate set of pumps and thermostats for the wood side.

You should be able to shut off just the burner with that red switchplate switch.

If the rads are hot a couple hours after you shut off the oil burner, then yes, it would mean that you don't have an airlock.
 
Is the unit set up with a tempering valve? Is this valve adjusted and operating properly?

cheers
 
Eric do you have two circ pumps, One on yor gas boiler and one on your wood? Do you have them wired together so they both turn on when needed? I had my oil off all night. the wood built p to a heat of 190* but he pipe coming out of th ob was cold as soon as I turned on the powr the pipe began to get hot . So it seems that I do needboth circ pumps. If I hook an aquastat from the wood to my themistat control and wire my two circ pmps together will I have controlable heat?
 
I have one big pump that gets hot water from the wood boiler into the gas boiler vessel and back. I have 3 separate zone pumps on the gas boiler that distribute hot water into the zones when the thermostats call for it. All have to be working for the system to distribute heat. All I do is shut off the gas burner, and the system operates like it normally would--the zones don't care where the hot water comes from. You must have a similar setup. The trick is finding out how to turn off your burner without turning off pump or pumps that push the heat up into your zones.

I wouldn't get hung up worrying about an aquastat until you figure out what the problem is. Your system should be able to heat your house without the benefit of the oil backup.
 
Can you just turn the aquastat on the oil boiler down? This keeps the oil boiler "on" but won't let it fire until the water temp drops below the aquastat setting... which won't happen as long as the wood boiler is pumping out heat. THis is if you are piped in series like Eric spoke of.

It's difficult to offer support when we can't see the piping. Got any sketches? Pics?

cheers
 
I second just turning down the temperature settnigs on the oil boiler. My piping set up is straight from the manual using the parallel design - the EKO is piped to run the wood-heated water through my oil boiler then back to EKO. My thermostat in the house turns on the oil boiler circulating pump to circulate the heated water through the house. I moved my oil boiler pump from the main return line to a tee from the supply as shown in the manual. It has worked great.
 
Rich R. said:
I second just turning down the temperature settnigs on the oil boiler. My piping set up is straight from the manual using the parallel design - the EKO is piped to run the wood-heated water through my oil boiler then back to EKO. My thermostat in the house turns on the oil boiler circulating pump to circulate the heated water through the house. I moved my oil boiler pump from the main return line to a tee from the supply as shown in the manual. It has worked great.

Hello Rich. Nice to talk to you again. I am glad things are working out well for you.

cheers
 
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