HELP with Espar heaters

The clip is like a tongue on top of the ecu. Stick a stubby flat blade between it an the box and twist. The top of the ecu will swing up and then pull it up. There are two claws that hook into the bottom of the box. You might be able to jump the two wires without pulling it out if you can see them.

Hello again Brian, I got a friends assistance and got the ECU out so just shipped it to Ocean Options in Rhode Island.
They downloaded 5 straight glow plug faults..., so now have 2 glow plugs coming & 2 pump screens.
They also said the heater only has 214 hours on it !
Also... since it turns out I do have just a modified three wire harness going to the thermostat is there any way short of replacing the whole harness I can use the digi-max to replace it with? Thank you ! Marc

What happened to the blower codes. You had a bunch, and no glow pin codes? I'm not optimistic! You need the brown. Red, yellow, and blue w/ white stripe. If they are not in your harnes. Then you will need a wire and terminal to insert into the Oval plug to mate up with the blue w/ white in the heater side of the harness. What series do you have. 252219? I have only replaced 0 glow pins in that model ever. Very suspicious of where the code 25's suddenly appeared from.

Brian... please see attached file. Does this help ? Marc

Brian silk said:

What happened to the blower codes. You had a bunch, and no glow pin codes? I'm not optimistic! You need the brown. Red, yellow, and blue w/ white stripe. If they are not in your harnes. Then you will need a wire and terminal to insert into the Oval plug to mate up with the blue w/ white in the heater side of the harness. What series do you have. 252219? I have only replaced 0 glow pins in that model ever. Very suspicious of where the code 25's suddenly appeared from.

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Sorry got you mixed up with another post!

The digimax is not compatible with the d8. I would keep it the way it is. And look for a 7 day timer pn 22 1000 30 40 00.
It needs 4 wires to hook up to. The brown (-), red(+), yellow- Switch on, and blue with white stripe. These are all in the harness coming out the top of the furnace. You can hook the 7 day timer up to the 4 wires, and just use it as a diagnostic tool. It will give you a digital code. Directions are a bugger. You have to make up a switch to mimic the ignition switch. Of a car. If you have the manual you will get the operating sequence.

Capt Kornchex.i made a mistake and mixed up answers. See my last post in answer to your last question regarding the multimax.

Yes thank you Brian... I got that.So, what did you think of the info in the print out ? Did that give you any good information regarding my unit?1 additional question.... does that seven-day timer replace my existing thermostat or is it in addition to ?Also is it possible to locate it (and the new "ignition switch") at the heater... or does have to be the same location as the current thermostat?Thx ! Marc

Brian silk said:

Capt Kornchex.i made a mistake and mixed up answers. See my last post in answer to your last question regarding the multimax.

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Hello again Brian... well I was happy yesterday. Re-installed the ECU and the new glow plug and everything was working fine. Come back down to the boat today and now not functioning again. Little bit different though I have only a red light on at the thermostat but no matter how high I turn the dial the green light does not come on does & not click or call for heat.Short of sending out ECU for another read of codes any suggestions?

Update... Found a loose 12v connection feeding the heater.Still not sure why red light only was lit when I first came onboard.But once I jiggled the connection, heater spooled right up. Will this store as a code on the ECU ??? Thx again !

No it will not store a code. Also, once heater has started successfully it does not stack up that failure contributing to the five fail lockout.
The 7 day timer is not a thermostat, so it would be wired up on the four wires mentioned before, and the existing thermostat stays connected.the 7 day would be mounted at the heater along with the ignition switch. The hours on the readout are low for a glow plug to burn out. Should be way more. Could be a bad glow plug, make sure you have a spare. Was the bad one all crusted with carbon, or just broken coil? Sorry for my slow reply, I'm going crazy busy right now.

To new member from oak harbour. System or i accidently deleted your message.

Here is my answer

Good day. It looks like the glow plug is going on(relay is the voltage regulator for glow plug). The motor is not turning, so check for a fuse on the bottom of the Pulse Generator. The smaller if the two boxes behind the bug rectangular face plate of the heater. It is a push and twist knurled knob.. it may also be an external fuse holder with a 20 amp fuse. If you find the fuse and it is ok then you need to find out if the motor has power going to it. Remove the hatch on top of the heater. Remove all three glow plug wires. Take out four phillips screws and swing the hatch open. There is a terminal strip. On the far left towards the motor you will see a black wire and a brown wire going towards the motor. Suspend all glow plug wires and turn on heater. Check for voltage on the two wires. Black pos. Brown neg. If you have power then the motor will need to be re brushed or has a bad commutator. , or both. If you have no power then it could be the logic circuitry in the Ecu- larger of the two control boxes. Send me an email to [email protected] and I will send you the manual. It had a good troubleshooting flow chart. If the motor is un -repairable then you must find a used one on the net, as they are no longer made or available. The ecu is, but $700 off dollars. I would not spend that on that vintage if heater. Sometimes the fuse holder in the pulse generator gas been jumped or bypassed, as it was weak, and redundant as the main breaker should blow if it overloads. You should also hear a buzzing at the glow plug. It is the spark generated by the spark generator coil next to the glow plug. Test by hanging the glow plug outside the heater with all wires attached. Neg or brown goes on the smaller tab on the glow plug. Careful that the glow plug does not touch the case. Or you. You should see the element glow and a spark from the center arcing to the outside shield of the glow plug. The motor, and the pulse generator make the fuel pump. With no motor turning, no fuel pulse is generated. Let me know what you find.

Hello Brian,

Happy New Year!

I have a couple questions to bounce off you. First, the D12L has been running ok with the inlet duct off, but discharge temp is still pretty high in my estimation, ~305 degrees. I opened up the discharge duct work to 6" to help. Anyway, it tripped on high temp once the intake air came up to 70 degrees. The .4amp breaker popped. once it cooled, I reset it, but the unit is not starting the fuel pump now. I manually pulsed the pump circuit and the unit fires up normal... Could it be the overheat sensor, or the breaker, or do you think it is the pulse module? Also I swiched the main circuit breaker for a 30A because the it would just blow immediately when the unit would go for spark at ~20 seconds in...

Thanks Brian.

dcsat said:

I got the unit running again, the .4 amp breaker was tripped, which in turn made the 25A breaker trip. Once I reset the overheat breaker, then the unit would start again, but the main breaker has been exercised too many times and now it trips halfway through the start up. I jumped it out for a test and the unit ran fine. I’d like to replace both of these, I think they are too sensitive.

I have a couple more questions if you don’t mind…

1.) The manual talks about a full and half heat setting. My unit has an updated airtronic Thermostat (the one with the on/off rocker and red/green LED, rotary temp.)
This thermostat doesn't seem to support half heat as it is only three wire. Could I install another switch to toggle between half and full heat? If yes, what wires get connected or lifted?

2.) I got the unit running on the bench, and it seems to run fine. How important is the flexible intake hose to be in place? Mine got crushed…
3.) The duct work seems to be too restrictive in the boat, causing the unit to overheat. In fact the duct work stated smoking it was so hot. The manual shows an optional temp reducer, is this still available?
The main duct leaving the unit is at least 5-6” round and then branches off multiple times. The inlet is pretty short, 4-5 feet 3” up sized to 4”
4.) Is it acceptable to have the exhaust take a square 90° turn into the stack pipe? Although it has been this way for a while, this seems restrictive to me.

I’m trying to determine what is different, the heater has been running in the boat since the early 90’s, and recently it is acting up.

-DC

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Brian,

another question, is the V7S still a current model? could it be used in place of the D12L?

Thanks Again.

Replaced a D8LC heater bought in 2000 with new D8LC in November 2014. After the 1 minute plus start up cycles, shifts to medium level but never shifts up to high level. Old heater used to shift back and forth between medium and high. Both heaters use the rotary 0-5 knob with a Honeywell house thermostat wired in to fine tune the temperature. Same footprint, ducting, exhaust, input air duct, etc. Any suggestions?

Hi just saw your post... I also have a D8LC installed.... tell me more about the additional thermostat you have hooked up please.

1-half heat is possible, but the heater carbons up. They were modified because of this.
2-the intake hose is very important , evn the slightest change can change combustion. Try to take out the crush as much as possible . It even has tuning holes in it, that when plugged noticibly changes combustion. You can still get the hose new from Espar.
3-305 deg should be ok righ at the heater, but the ducting may be an issue. temp reducer not avail.
The intake MUST be minimum of four inches. If it is three inches, that may be your problem. If that does not solve the problem, then email me a schematic of the ducting with lenghts and diameters, branches etc.
4- 90 degree elbow is supplied by espar and is correct.

The .4 amp overheat breakers can get weak and pop off intermittently . I have replaced many. Still avail., but $156 I think

Puzzling. Who supplied the original?, and the new one. In BC we modify the harness to make them run on high only, which makes them run on high , and they seem to switch down to Low when the outlet endhood temp sensor gets hot. If it only runs on Medium- actually low. It may have a high limit switch built in, but have never seen one. when it is modified to run on high, two resitors are soldered into the harness to mimic the 0-5 knob in "5", or high-heat resistance signal to ECU, and then thermostat just turns furnace on and off. Roton used to do this by installing the rotary dial in the harness, turning up to high, removing the knob and taping it up so it could not be changed. Is the rotary turned all the way up?

Check out my answer, to that post.

Hello again Brian.... following along here because it's also a D8 LC. Mine is been working great since the glow plug was swapped. Quick question though noticed you said you need a minimum of 4 inches intake hose. Mine has absolutely none on the intake side of the unit is that a major issue? It simply draws air from the locker it's in and the generator is located there as well. Also I'm very curious about an additional thermostat is installed for temp fine-tuning. Is that something I can add in addition to the seven day timer for diagnostics?

Hello All, Happy New Year!

I am trying to complete connecting up a Espar Hydronic D5W S. The prior owner had started it but not yet completed it. Unfortunately, I don't have the documentation for the controller board (pics attached). It looks almost complete. The wiring from the Espar to controller is connected. It appears that only the fuel pump and battery need to be connected. The Espar documentation indicates brown and green from the D5W go to the fuel pump. The brown and green on the control board are connectors labeled "MP" (Maybe Motor Pump?)

There is no external controller/thermostat for the unit. The controller has 10 connections for 2 zones (white connectors near top of pic). I am hoping I don't need a zone thermostat and that I can hook up the fuel pump and battery and away we go...

I have an Espar AirTronic heater and it does indeed have an external thermostat. I know that when I turn the air heater off, the unit goes through a cooling off cycle. You definitely shouldn't turn the battery power off prior to letting the unit go through the cooling cycle. Is that the same for the Hydronic? If so, I will have to make some connection to a Zone 1 pin to control on/off while leaving battery power on to the D5WS.

Any input would be appreciated.

You do not need an intake, unless you want to draw inside air from the boat to re-circ. Or actually duct to the outside. It is safer to draw air from away from the heater as an exhaust leak could be sent into the cabin, but the heater cannot have 3"diameter duct attached to the intake. Width, not lenght. You can have a thermostat and 7 day timer, the thermostat needs pos, neg, and a wire going to furnace yellow, if it is already modified for high/ off operation. Thec7 day timer needs red, brown(neg), yellow, and blue for diagnostics. If the furnace is running on high/ low mode then it is wired up differently. What control do you presently have?

I have the small black thermo with a single rocker/rotary dial and 2 red/green LED's.
I would love to be able to add a digital/programmable thermostat. Is there a type that I would need to look for or specifically avoid? I will assume a typical home thermostat (ie: Honeywell) would not work. So does that leave me only with a Marine specific unit ?
I do not think it operates on low except during start up when I can hear an increase in fan speed once it is fully ignited. As far as the intake hose is there a minimum size for it? There is an area I can extend it to which is only 2 feet away... So should it be a min of 4 or 5 inches diameter if not the 3" of the intake ? Thanks again Brian.

What is the proper fuel ine to use with an Espar heater on a boat? I would like to replace the clear plastic line with something more substantial, is that acceptable?
thanks...

The intake end of the heater is four inches. That is the diameter of ducting to use. If you do go 2 ft. To an intake grill, it must be very free flowing. I only use the 4 " Espar heater delivery vents. You cannot use the commonly available vents used on boat,eg. Perkins, or sea dog. Their louvres are too angled and restrict airflow. Also the air vent will be quite noisy. There is a 4" intake muffler available from espar. $100 about. It does a fantastic job if quieting.

If you have only three wires in your thermostat then it runs on high only. You can install a Honeywell Pro 2000 battery operated programmable thermostat. Take the wire in your thermostat terminal 1(pos.) and put it in the "R" terminal on the honeywell. The wire in terminal 2 goes to the "W" on the honeywell. The wire left over is in # 4, it is ground and not needed. Done it many times.

Hi Brian,
I have an Espar heater, which I installed myself. This past weekend it shut down after a brief period and when I checked fuel, power, etc., I observed the coolant was low in the reservoir. I filled the reservoir and the heater started up and worked like a champ. I then noticed that coolant was coming out of the overflow hose and wouldn't stop. Is this a matter of too much coolant or is something else happening. It wouldn't stop, so I shut it off. Thanks for your feedback.

Sincerely, Mark

If the heater is running properly, not overheating and shutting down, then the expansion may be normal. There is supposed to be a pvc hose attached to the top of your header tank going to a recovery bottle. Just like a car or boat engine. The fluid gas to expand. If this happens within 2 minutes of startup, approx. Then you may have a flow problem and are boiling the fluid. It usually takes five plus minutes for the rad cap to open up.

Thanks Brian. I missed that step. The whole installation process was quite a revelation, but I feel like it is almost dialed in. Thanks again for this service you provide.

Mark

Brian, I have an Espar Hydronic D5WSC that you may or may not have installed in my new Hunter in the spring of 2012. The furnace is located aft of the after cabin, along with the boats diesel fuel tank. The Espar exhaust output is located in that compartment feeding to the outside. Currently the make up air (combustion air) pipe is about a 18" long and thus in the same compartment. My question is: Should the combustion air originate from outside or is it okay to be drawing from inside air? That compartment is not totally air tight from the outside but I would say that it would be about a 80% inside/20% outside mix. It would not be too difficult to source the combustion air 100% from the outside air.

Hello. It is fine that way. Plenty of air will get in from locker leakage. We have been doing it like that for 30 years or so. Only if it was a gas engine would it be safety issue. Not to worry. Cheers.

Brian silk said:

Hello. It is fine that way. Plenty of air will get in from locker leakage. We have been doing it like that for 30 years or so. Only if it was a gas engine would it be safety issue. Not to worry. Cheers.

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Thank you very much fro the quick reply, Brian. It is comforting to know that all is well back there.

Len