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.
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?