Espar Mystery

[Auspicious]

Originally Posted by Sandero

I have an Espar Aitronic4 which was installed in 2007 replacing an Espar D3L.

It's unlikely to be the thermostat. That is just a switch.

Fuel pump sounds right - it's an impulse pump that sends one squirt of fuel each time 12VDC is applied. If you put a good DVM on the fuel pump leads you should see the power go between 0 and 12(ish) volts rather rapidly. Similarly if you set up a 12V supply you should be able to get one squirt of fuel from the pump each time you touch it to the pump connections.

There are a handful of sensors - flame out, ambient temperature, blower - and a couple of relays, the control box (the silver thing with two multi-pin connectors), and the small board inside the heater.

In order of what seems likely to me: a loose connection (sometimes the pins in the connectors get bent), a bad control box, or a bad board.

Check the connections and connectors and the fuel pump. If those are okay you better send it in to someone.

Disclaimer: the company I work for services diesel heaters.

[darylat8750]

When I'm having an intermittent, "kinda, sorta, trying to work" issue I always check system ground wires. A little corrosion in the ground circuit can really confuse electronics.

[Sandero]

The pump is brand new so it's not the pump per se. I've cleaned and DeOxIted all the connections. The 12v wiring is new 2013 and clean as a whistle..

It's a control problem... and it's in what I am calling the thermostat which calls for heat or tells the heater relax no need for it. Or inside the unit and a control board. I can and will remake and replace the fuel hoses as perhaps there is a blockage and the unit is fuel starved... but there's no leak... that's for sure... and go over the wiring one more time... before I return the T stat and the unit for Espar's service. When it was sent a month ago with the now replaced pump (which was acting intermittent and then stopped... but maybe that's a control issue too.... I'll send them the old pump for testing as well)... both the pump and heater ran fine on their bench on Kerosene. And showed no error codes.

Of course an intermittent electrical connection or cracked board can be hard to find.

The heater DOES at time work for a few minutes before shutting down... but work not at normal full output. I don't recall of there was a mode between full on heat production and the more quiet mode when the design temperature has been reached.. so when it's working for those few minutes it seems to be something between the full on heat production and the quiet maintenance mode.

This middle performance seems like a fuel issue... not enough fuel to get things hot enough and so the fan is slowed down.

I'll do the hose thing and if doesn't work, back it all goes to the pros.

[CampDavid]

Suggestion, remove the fuel line at the bottom of the heater, remove both electrical wires from the pump. SYSTEM TURNED OFF.

Now take a jumper from a 12 volt source, if you have a small agm 12 volt battery they work great. connect the negative to the pump, now touch the positive to the pump, just for a second or two, keep this up until you see fuel spiting out of the end of the fuel line. You will hear the pump click.

This is the action that occurs when the Espar is running. The pump continually cycles. If it takes a while to get the fuel to the end of the line, you have or had air in the system, if it does not come up then you have a pump or an air leak problem, if fuel comes out very quickly then I would think the pump and lines are and were working correctly.

If you have a filter in the line, change it first,

The unit shuts down after a set number of attempts to ignite, if the fuel is not getting there early enough the brain shuts the system down,

Be sure you have fuel at the heater before you attempt to ignite the system

I am not sure which wire stat you have, if it is the square one there is one wire that is not connected, it needs to read the temp at the state versus the intake air.

Good luck,

Fletch

[Sandero]

Originally Posted by CampDavid

Suggestion, remove the fuel line at the bottom of the heater, remove both electrical wires from the pump. SYSTEM TURNED OFF.

Now take a jumper from a 12 volt source, if you have a small agm 12 volt battery they work great. connect the negative to the pump, now touch the positive to the pump, just for a second or two, keep this up until you see fuel spiting out of the end of the fuel line. You will hear the pump click.

This is the action that occurs when the Espar is running. The pump continually cycles. If it takes a while to get the fuel to the end of the line, you have or had air in the system, if it does not come up then you have a pump or an air leak problem, if fuel comes out very quickly then I would think the pump and lines are and were working correctly.

If you have a filter in the line, change it first,

The unit shuts down after a set number of attempts to ignite, if the fuel is not getting there early enough the brain shuts the system down,

Be sure you have fuel at the heater before you attempt to ignite the system

I am not sure which wire stat you have, if it is the square one there is one wire that is not connected, it needs to read the temp at the state versus the intake air.

Good luck,

Fletch

Thanks Fletch.

The pump is brand spanking new.
The pre filter is new

Your suggested means to test the lines makes sense. I'll try this. Obviously SOME fuel is getting to the heater and the pump IS clicking. I recall from memory that when it goes into serious start up the pump clicks pretty fast... obviously responding to the demand for lots of fuel to get the plug hot... then, as I recall... the click rate (pump rate) drops down... sort of supply enough fuel to maintain the heat as the air is cooling it, becoming heated and then sent through the ducts to the cabin. In shut down there is no combustion but the air continues to blow (gently) cooling the plug.

The system is fuel staved or the controller is "confused" or both! The captain certainly is.

[GeoPowers]

Flame sensor. Will write more inthe morning

[GeoPowers]

Morning! I had similar issues with my diesel heater, and it ended up being a combination of coking (which you've taken care of now that you had the unit serviced), and a poorly performing flame sensor. I have a Webasto, and I'm not familiar with Espar's specific internals, but here's my thoughts:

1. Your unit ran fine for a period of time before your current issues, so unless a fuel line was recently re-routed or pinched getting fuel from your tanks to the heater shouldn't be the issue.

2. The fuel pump and glow plug are new, so you are getting fuel to the heater and heating it up. Both are fairly simple and reliable components, so doubtful that either would fail again.

3. You mentioned a build-up of smoke in your first post. Was this white smoke? I've observed this happening where a diesel heater kept shutting down during start-up, but fuel that was delivered to the combustion chamber didn't completely burn away. Does this happen often, or just once?

In my problem, it turned out the flame sensor became coked/fouled at a micro-level. In other words, you could make it look clean, but it needed replacing. For a temp fix, you can use very fine sandpaper to create a clean surface, but the abraded/coarse surface of the flame sensor will then foul quicker.

The only thing about your problem that doesn't sound like my situation is your description of a loss of pressure:

"...It began to produce heat through the ducts. But the pressure was weak and the temp not especially hot. The exhaust gases were likewise not as hot as they use to be, no smoke at all and the pressure considerably less. When working properly I recall you could not put your hand over the the exhaust thru hull because the gas was so not. Not so now."

It is difficult to guess what would cause this since the unit was inspected/ bench tested.

Best of luck in figuring it out!

Frank

[Sandero]

Originally Posted by GeoPowers

Morning! I had similar issues with my diesel heater, and it ended up being a combination of coking (which you've taken care of now that you had the unit serviced), and a poorly performing flame sensor. I have a Webasto, and I'm not familiar with Espar's specific internals, but here's my thoughts:

1. Your unit ran fine for a period of time before your current issues, so unless a fuel line was recently re-routed or pinched getting fuel from your tanks to the heater shouldn't be the issue.

2. The fuel pump and glow plug are new, so you are getting fuel to the heater and heating it up. Both are fairly simple and reliable components, so doubtful that either would fail again.

3. You mentioned a build-up of smoke in your first post. Was this white smoke? I've observed this happening where a diesel heater kept shutting down during start-up, but fuel that was delivered to the combustion chamber didn't completely burn away. Does this happen often, or just once?

In my problem, it turned out the flame sensor became coked/fouled at a micro-level. In other words, you could make it look clean, but it needed replacing. For a temp fix, you can use very fine sandpaper to create a clean surface, but the abraded/coarse surface of the flame sensor will then foul quicker.

The only thing about your problem that doesn't sound like my situation is your description of a loss of pressure:

"...It began to produce heat through the ducts. But the pressure was weak and the temp not especially hot. The exhaust gases were likewise not as hot as they use to be, no smoke at all and the pressure considerably less. When working properly I recall you could not put your hand over the the exhaust thru hull because the gas was so not. Not so now."

It is difficult to guess what would cause this since the unit was inspected/ bench tested.

Best of luck in figuring it out!

Frank

Frank,
Thanks for taking the time to write this reply.
I don't recall when the problem first manifest. But I noticed something odd when using the heater to cut the chill in the summer. It came on but never seemed to pump out a lot of heat. At the time I attributed this to not very cold ambient air temps.

The first set of fixing was to replace the pre filter then the fine mesh screen in the metering pump. It was then I noticed that the pump itself was not coming on and the unit began to really appear to be not functioning properly. Espar told me to check the electrical connections to the pump... which I did to no avail. The pump now would not start. Rather than replace the glow plug screen I sent the pump and the heater for service.

Espar ran them on their bench with kerosene after replacing and presumable cleaning the glow plug. They said it worked fine and there were no error codes recorded. I reinstalled it and the pump would not work. I was told to check the resistance and that seemed low and so I ordered a new pump which I installed. The pump DOES work.

When I got the unit back from Espar it I did manage to get it to work once or twice for a few minutes before it crapped out. I recall the first "success" produced a lot of exhaust smoke which spread through the cabin. The heater is installed under the berth CL aft of the engine and batts about 4'-5' feet from the transom. Since this all began I've not seen much of any smoke coming out the thru hull... but some hot gas is (not as hot as it used to be). I suspected blockage in the exhaust hose and ordered a new one... I have no installed it... yet.

The smoke was whitish blue... hard to tell... it spread throughout the cabin and was awful but not dense. This never happened again.

Perhaps I should experiment without the exhaust hose attached? If it works normally it would then indicate there is something fouled inside the hose.

The failure to produce high heat seems to be a control issue or something preventing full on combustion. The htr will roar for a some time when it does try to start.. the pump clicks furiously but then it stops and goes into a sort of quiet mode without producing much heat and then seems to shut down after several minutes completely. To me this means the htr and t stat think there is no need for any heat... or else it would restart.

I'm baffled... and tempted to send the thing to Espar once again.

Jef

Fabulous blog!

[darylat8750]

If you haven't checked intake and exhaust ducting by all means do. Is it possible for birds/insects to build nests in the exhaust?

[senormechanico]

I was just going to post the same thing. Exhaust restriction!
This explains the smoke in the cabin, the poor combustion, everything.

[Sandero]

A bit of an update.

I suspected that there was problems with the exhaust hose... I probed it a bit with a snake and it seemed OK. But I order new exhaust new exhaust hose.

Went to the boat and flip the Espar on and it went into a 4 minute cycle before shutting down. It did produce some heat (sub par). So I decided to replace the fuel hose and see it that had any effect. Fuel pump would not work... no pulses. Check and cleaned the connections and then decided to send the entire thing to Espar for service. In the process of remove the exhaust hose I found it broken about 8" from the heater. It was visible because it was sleeved inside of some 3" ducting to prevent anything from touching the hot hose. Obviously I put the new hose in... when the heater comes back "fixed" and bench tested... If it doesn't work it can only faulty (corroded) wiring of the harnesses.

Exhaust restriction would not cause the heater not to start or the pump to not come on... but it might and should shut it down.

I expect the heater back in a week or two.

[RDW]

Your problem is likely in a portion of the system not sent in to be bench tested. If I read things right that would be the thermostat and the fuel line and pick up. Be careful in how many times you try to start it up because on mine if you get a few false starts it will shut down. You may want to disconnect the fuel line at the heater and use jumper cables (on mine positive and negative are either way and not marked) to activate the pump to see if fuel is being delivered.
If fuel is being delivered, I would think it is the thermostat.
Be sure and let us know the end result.
RDW

[Sandero]

Originally Posted by RDW

Your problem is likely in a portion of the system not sent in to be bench tested. If I read things right that would be the thermostat and the fuel line and pick up. Be careful in how many times you try to start it up because on mine if you get a few false starts it will shut down. You may want to disconnect the fuel line at the heater and use jumper cables (on mine positive and negative are either way and not marked) to activate the pump to see if fuel is being delivered.
If fuel is being delivered, I would think it is the thermostat.
Be sure and let us know the end result.
RDW

RDW,

Excellent analysis.
I suspected the T stat, but I am not sure how much control of the heat it has. My sense is that if the T state is not satisfied (air not warm enough in cabin) the T stat "tells" heater to produce heat.

The heater seemed to have two basic heat modes... high output and sort of a maintenance mode. The later would have the heater running but with less fuel being burned and the blower ramped down. In the shut down mode no heating takes place the the blower continues to run until the unit cools down and it does blow mildly warm air into the cabin.

My unit tried to function in the high output mode and it seemed somewhat normal except for diminished pressure at the outlets... hard to tell. It would only remain in the mode for 4 minutes or so and go into shut down mode. I could do this sequence a few times... and then (yesterday) the pump stopped working and so there was no start up high output phase. That's when I decided to send the heat, the pumps and the t stat to Espar again. My sense is that there is no fuel blockage at the pick up... but it's a possibility... the 1 mm clear fuel line appears to be full of fuel. Obviously it could still be blocked, but would a blockage cause the pump to cycle faster? Or does the heater not meter the inflow manage the pump?

Lot's of mysteries here. I don't think it's a voltage problem or wiring... there nothing left in the boat to trouble shoot once Espar returns a working heater, T state and pump. As noted above I will be changing out the exhaust hose.

Thanks for your suggestions!

Jef

[goboatingnow]

Just step through the sequence

If you are getting ignition , ie you can hear the flame establishing , is it stable, sometimes you can hear a stuttering firing sequence.

If you are getting stable flame . But then shutdown , then

(A) you have a control board problem , have you sent the control system to Espar

(B) flame sensor failure

(C) fan motor not coming up to speed

(d) low voltage during the firing sequence


If you are experiencing unstable flame
(A) fuel flow
(B) exhaust restrictions
(C) coking
(D) jet blocked or worn.



Dave

[Sandero]

Originally Posted by goboatingnow

Just step through the sequence

If you are getting ignition , ie you can hear the flame establishing , is it stable, sometimes you can hear a stuttering firing sequence.

If you are getting stable flame . But then shutdown , then

(A) you have a control board problem , have you sent the control system to Espar

(B) flame sensor failure

(C) fan motor not coming up to speed

(d) low voltage during the firing sequence


If you are experiencing unstable flame
(A) fuel flow
(B) exhaust restrictions
(C) coking
(D) jet blocked or worn.

Dave

Thank you!

There seem to be multiple problems!

I concur it is a control "board" problem and that includes the T stat.

I don't know about flame sensor... but that makes sense. As the flame WAS established in several "tries" to run the heater... it leads me to think the is no fuel delivery problem. But after the things get going it doesn't seem to have enough pressure from the fan... kinda of a guess... it's hard to tell. The air just doesn't seem to be hot enough and blowing hard enough from the outlet. This subjective. So fan motor may not be coming up to speed.

I don't think the voltage seen by the unit is inadequate. The take off is from the batts and the Link is reading 13+ as it's on a battery charger. Perhaps the unit is not supplying enough current to the glow plus? I don't know how this works.

Exhaust restriction is a possiblity. After removing the unit I discovered the exhaust corroded and parted close to the heater... which explains some of the fume smell in the cabin and the weak pressure and heat at the exhust. The stainless exhuast hose was at the heater was a hot as a fire cracker as expected so there was combustion.

The mystery is the fuel metering pump which is brand new. After a failure to operate for more than 4 minutes I decided to replace the 1mm and "splices" and clamps. When I tried to restart... the pump would not come on. And that's when I decided to simply send the lot back to Espar and when I discovered the broken exhaust hose.

At this point all that can be done is "guess" what Espar will find and recommend. The heater worked fine for 6 years... flawlessly. And then seemed to begin a "weak" heat phase and then the pump began to act whacky and was replaced along with a screens and filters.

I think it's a control issue and it may be an intermittent one like a faulty board connection... But I am at a loss to explain it as I don't have test equipment except a VOM... It's over my depth... I am off to the PO to ship it back to Espar.

Stay tuned!