Espar Mystery

[Sandero]

This may be a long post. I apologize.

I have an Espar Aitronic4 which was installed in 2007 replacing an Espar D3L. I reused the old ducts but everything else was new. It worked perfectly up until this past summer when I turned it on a few times on cool nights. It seemed to be unable to produce enough heat no matter where the thermostat was set. I thought maybe the ambient temps were not low enough for the program to kick into high output. But in the fall when they were the same occurred.

The the metering pump seemed to be intermittent. No fuel no heat. I assumed that there was fuel delivery problem so I obtained replacement screens for the pump, the glow plug and pre filter. No joy. Then the pump stopped working.

I sent both off to an Espar service center. They bench tested (operated) them, cleaned the plug and did the actual screen replacement on the plug and sent it back telling me it was fine.

Reinstalled and nothing. Pump was acting very whacky. At one try the unit fired up produce some thick smoke which somehow did not get directed out the exhaust hose... something that never had happened before... exhaust gas INSIDE the boat. Anyway it stopped and the pump now refused to work.

I contacted the service center who suggested I measure the resistance at the pump and the harness pins to the pump. I was looking for 9 ohms. I got 8.4. I asked them to send me a new pump and exhaust hose. If the new pump worked I would then change the exhaust hose... removing the old inspecting it and if damaged replace it, if not send the new hose back.

I cleaned all electrical connections and sprayed them with DeOxIt. The 1v mains were newly wired in 2011 and the wiring clean and oversized.

The start up cycle with the new pump seemed strange but I never had closely observed it so who knows? The blower came on first, then the pump pulsed slowly and finally it sped up and the unit roared rather loudly and seemed to be in combustion mode. 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.

After several minutes of running in what appeared to me to be a below spec mode, but producing some heat and air flow it went into "shut down mode"... pump stopped... blower remained on for a while blowing not very warm air. No exhaust gas and obviously no combustion.

I waited and tried restarting at different thermostat settings. Sometimes it just wouldn't start at all other times it would repeat what is described above.

Something is not working correctly and I am trying to identify what it is.

It's not:

the pump
the wiring
the voltage at the unit
blockage of the ducts

Probably not blockage of the exhaust system.

If the unit was bench tested and run with kerosene to clean it out I am thinking glow plug is fine.

I am thinking there is a "control issue"... and it may be an intermittent one. Hardest ones to find.

Do you people think it could be the thermostat?

Dealer wants me to send him the unit and the thermostat. Or perhaps he should send a new thermo stat which I can install and see if that solves the problem. If not return the new thermostat with the unit so he can sort it out.

Any idea about this?

[witzgall]

It sounds to me like a fuel delivery issue. THe start sequence is just like our Webasto, so I think that may be ok. The pump is only one part of that system - the line could be partially blocked, or improperly run, or both.

Describe exactly how the entire fuel system is plumbed and laid out.

Chris

[Sandero]

Originally Posted by witzgall

It sounds to me like a fuel delivery issue. THe start sequence is just like our Webasto, so I think that may be ok. The pump is only one part of that system - the line could be partially blocked, or improperly run, or both.

Describe exactly how the entire fuel system is plumbed and laid out.

Chris

Thanks for the reply. This was my original thinking.

The system has been working for 7 yrs without a glitch at all!

I contacted Espar Service and discussed it and they sent me a new pre filter, and the micro screens for the pump and the glow plug.

The old pre filter was pretty dirty and I though ah ha I got the problem. Wrong would not fire up. At the time the pump seemed to be OK but not fire up so next I did the pump screen. YIKES filthy. Now I thought I am good to go. No joy.

At this point I decided to let Espar change the glow plug screen test and clean the heater... and evaluate the pump.

They returned it having replaced the screen, presumably cleaned it and said they bench tested and ran kero and it worked fine. Once reinstalled it did not and now the pump would not kick on. No pump. No fuel No combustion.

I used a syringe to introduce some fuel into the hose and the unit fired up and ran for a few minutes until the fuel in the hose was consumed.

Called them and requested a new pump. I did the resistance test at the pump they requested. resistance was low. They sent a new pump.

Once installed it worked. But heater will not stay on and seems to "think" it does not need to supply heat. And when it DOES it stays on for a few minutes, does not burn very hot or produce much air pressure in the outlet either of the exhaust of the hot air.

The fuel lines are "full of fuel" and I can feel the line pulse when the pump pumps.

[witzgall]

I was more interested in how you are getting fuel to the heater. Describe the fuel system installation in detail.

Do you have a thermostat that shows error codes??

Chris

[Sandero]

No I don't.... it's a pretty crude thing...

There is a fuel pick up in the diesel tank... plumbed via a 1/8" hose to the pre filter about 36" or so... then a smaller short hose from the pump to the very small nylon hose... the ID is tiny less than .125 ... which is about 5 feet and connects to the htr. The pump is set at 15° as required.

[senormechanico]

Fuel nozzle in the combustion chamber might be plugged.
I had to replace one in my previous boat.
The nozzle would occasionally get plugged.
Turned out to be a tiny piece of solder when manufactured !

[Sandero]

Could be.... I am likely going to send it back to Espar... I don't have the patience or the experience to tackle it and can't read the error codes either.

Thanks for the great suggestions. I'll let you all know what it turns out to be when I find out.

You guys are super... I really appreciate your thoughts and experience.

[Badsanta]

I would disconnect the fuel line at your heater then turn on your fuel pump to make sure the line pickup to your device is clear. It would not take much to block it.

Sent from my SPH-L710 using Cruisers Sailing Forum mobile app

[Sandero]

When the pump is on... I can feel the fuel hose pulsing and I assume this is from the fuel inside... why else would I feel this if there was no fuel going through the tiny hose?

[btrayfors]

The pulsing might be a result of vacuum/pressure created by the pump.

I'd rig up a temporary alternate source of fuel. The pickup in the diesel tank might be partially clogged. With a "day tank" substitute, you'd know for sure rather than guessing.

FWIW,

Bill

[senormechanico]

Last summer I got a fellow boater's genset running.
He was convinced his fuel pump was bad and had already made a call to order one at something like $350.
I took a look at his fuel pump inlet, showed him the total blockage, and blew it out backwards with a short hose connected to the outlet.
I just gave it a hard puff by mouth, and the pump worked perfectly.
It probably was a different pump/valve arrangement, but it couldn't hurt to give it a try.

[witzgall]

I will second this suggestion. If you see fuel coming out each pulse, then you most likely can eliminate fuel supply as an issue. If it is an issue, and you send it to Espar, the most likely result will be that they send it back to you with "No problem found".

Chris

Originally Posted by Badsanta

I would disconnect the fuel line at your heater then turn on your fuel pump to make sure the line pickup to your device is clear. It would not take much to block it.

Sent from my SPH-L710 using Cruisers Sailing Forum mobile app

[goboatingnow]

Sounds very like a burner nozzle /jet issue to me. The ignition is occurring but flame stability is not being established. Once you've eliminated fuel delivery it's usually the jet.

Note ensure you remove air from the fuel line . Pull the fuel line at the burner and run through an ignition sequence ensure good fuel delivery at the pipe endpoint. Sometimes you cannot clear air without removing the back pressure of the burner , hence the need to pull the pipe

Dave

[VanIsle]

I had a similar problem in my 3DL. Unit would start, not develop full heat, then shut itself down. If I restarted it, the same sequence would repeat. Turned out to be a hairline crack in the motherboard. Serviceman replaced the board and it worked great thereafter.

[Sandero]

Originally Posted by VanIsle

I had a similar problem in my 3DL. Unit would start, not develop full heat, then shut itself down. If I restarted it, the same sequence would repeat. Turned out to be a hairline crack in the motherboard. Serviceman replaced the board and it worked great thereafter.

This sounds like a plausible explanation. I think... I'm not sure... at one time I sort of jiggled the unit in the non starting start-up sequence and it seemed to wake up. I can't connect the two but perhaps there is something loose or intermittent which because the unit has vibration etc can cause it to shut down.

I am convinced it is a control issue not a fuel delivery one. But I am perplexed that when it does fire up it's not working full on.