Brian silk
Regular Contributor
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First. I would be double checking the pc board. If you are sure the solders are good, I would then assume that the ecu- control box is defunct. Too expensive. $700 to invest in an old heater with old blower. Again. The flame tube would be good to look at.*Regarding the overheating D5LC:
Got the new overheat switch, it tested same temp range as older one.
Installed the heater, overheat tripped in 7 minutes.
Stuck a multimeter probe in the duct, it showed 190 when the overheat tripped.
What do you think of the new Airtronic 5 L?
I just wanted to put it out here that I can give service advise on ESPAR brand heaters. I have been an Espar Marine tech for 16 years and know them inside out. You can message me privately if you wish. I will check the General forum regularily.
Hi Brian. Have an diesel Espar Hi. #1. Check the voltage on the bottom of the control unit. Red and brown wires in a two pin plug housing. Check before you turn it on, and then turn it on. If the voltage drops below 10.5 then you have a bad connection in the power harness. Very possibly the fuse holder near the battery terminals. If it is ok then check the fuse on the bottom of the control unit. It is for the motor. It is a funny 4 amp slow blow fuse. You have to get it from a dealer, or electronic store. If it is blown it usually means the motor or bearings in the blower are toast. If it is ok check the overheat switch. Press down on the rubber boot up on top of the case. If it clicks then it has overheated. It will reset. If it does not click then obviously it is ok. If you can. Remove the boot and look down inside( probably not,as they are usually crammed up too high. Sometimes the terminals(small push on spades) can be corroded. If they are the you need to remove the heater and case and clean up and replace the spades. Check also that the fan is free turning. If it is not, then the blower has probably seized. Heater goes in garbage then! If all this is ok,then I would probably suspect the control unit. It may be dead,again heater goes in garbage. You can try cleaning up the relay contacts with some Emory paper. Remove the control unit, remove the tape at the bottom, pry up the little aluminum tabs and pull the plastic bottom housing off. Then gently pull out the circuit board. Look for burning anywhere. If it looks ok the clean the three relays contacts. You can tell which one the motor is by putting the plugs back in and pressing the relay ends until one activates the motor. If cleaning does not do the trick then it is toast.
Obviously, check the entire wiring harness and plugs for corroded or loose connections. If it is a 25 1640 then it has a simple open close thermostat, if it is a 251738 then it needs resistance sigmal from the thermostat, wiring connections in the thermostat harnesss are more important.
You can check the glow plug element for eroded spots on the coil, they will glow hot and the rest will not, or there may be a broken coil that may be barely making contact. Do a continuity check between the threaded stud and the flat disk, should be a closed circuit. You can also hang it outside in midair with the wires connected and turn the heater on, weak spots will glow, or if it is a barely connected break, it may spark. There is a small posibility of one of the glow plug relays being bad-the two in the harness. Hope this helps. Post a reult if possible
I just wanted to put it out here that I can give service advise on ESPAR brand heaters. I have been an Espar Marine tech for 16 years and know them inside out. You can message me privately if you wish. I will check the General forum regularily.
Yes. Still on it!
It is one of two things. The flame sensor on the top of the heat exchanger, under the black metal case on the hot end of the heater. It may be stuck on hot, so when the heater turns on the ecu thinks it is hot and goes into cooldown and stays there. Or the ecu is fried. To test you need to take the heater off its bracket. Remove exhaust elbow, fuel line and intake off the bottom. Unbolt th heater from the bracket. Undo all the horizontal row of case screws from the front and back. Undo all four of the screws that hold the hot end plastic endhood. If you look at the top hot end, you will see a sensor with a wire going to each side of it.put a jumper across the two terminals and start the heater . If it now turns on the glow plug, and the fuel pump turns on at 25 seconds then it is the flame sensor. If not then the ecu. If it is the flame sensor then good, because you can still get them. , and under $100. If the ecu is bad then $700. Throw out the heater! Not worth it. Obviously. Thus is only applicable if you heater is a 25 1640 model. Not a 25 1738. Numbers are on the tag on top of the heater. If it is a 1640 there will be three plugs in the ecu, if a 1738. Only two plugs. Let me know how that goes. If it is the temp/ flame sensor you will need to remove the galvanized heat shield that covers the flame sensor. It has two little "speed nuts" that push on to little nipples. You gave to carefully pry open the leaves of tgese little clips so you can pull them up and off. Makes more sense when you are looking at them.
Hello. I would need to know what series it is. A number on the tag that starts with 25. If it is older without a replaceable atomizing screen then the burner is clogged. New burner. If it is one of the newer ones it will have a replaceable atomizing screen $17. But a bit complicated to replace or explain. Get me that # and I can try and get you the troubleshooting / repair manual. You would have to email me at avalonbaymarine.com contact form on site. I would have to talk to you while you are looking at the manual.