Strange Diesel Heater fault

[not done it yet]

One problem with analysing problems, with electric/electronic kit, is that voltage is regarded as the be-all-and-end-all check. It is not.

Supply voltage may be present without any current being passed - and with no current, power dissipated is zero. Likewise a zero voltage may mean a dead short as well as no supply.

My 4kW (not really 5kW, as advertised) in my workshop has given no problems since installation, but the 2kW (really ~ 1.6kW?) heater has failed - possibly because the fan speed was slightly slowed by the much- extended warm air delivery tubing (even though increased to 150mm) and being run at low Hertz fuel-delivery.

I have burned-out the combustion chamber as the internal gauze (not the atomising gauze around the glow plug) appeared to be at least partially blocked. Heating the combustion chamber on the cooker ring, and feeding in an oxygen supply from my oxycon, hopefully burned off the carbon and not the gauze! I’ve yet to test it, but hope it will fire up properly when I get to it.

 

[slim_boy_fat]

It lives!! My modem chose to self destruct late afternoon so been interweb-less until today [replacement only arrived today despite ISPs promises [but that's for another thread....]

Sat a.m. I cleaned the entrails and bled the system and it eventually fired up and is back to full strength .
Appreciate all the responses/suggestions - happiness reigns again at Slim Towers!!

 

[OJCar]

It lives!! My modem chose to self destruct late afternoon so been interweb-less until today [replacement only arrived today despite ISPs promises [but that's for another thread....]

Sat a.m. I cleaned the entrails and bled the system and it eventually fired up and is back to full strength .
Appreciate all the responses/suggestions - happiness reigns again at Slim Towers!!

"Modem" ... Forsooth! Verily which Millennia art thou computing from !

Glad your back and keeping warm!

 

[slim_boy_fat]

"Modem" ... Forsooth! Verily which Millennia art thou computing from !

I suppose I should have referred to it as "the router", but the folk at the ISP understood fine.

 

[JOEPRO]

It lives!! My modem chose to self destruct late afternoon so been interweb-less until today [replacement only arrived today despite ISPs promises [but that's for another thread....]

Sat a.m. I cleaned the entrails and bled the system and it eventually fired up and is back to full strength .
Appreciate all the responses/suggestions - happiness reigns again at Slim Towers!!

How old is the Heater?

How many hours a week roughly is it ran?

What fuel do you use?

It seems strange that one would need disassembled and cleaned out internally.

 

[slim_boy_fat]

How old is the Heater?

How many hours a week roughly is it ran?

What fuel do you use?

It seems strange that one would need disassembled and cleaned out internally.

a) Can't recall exactly, but 2>3 at a guess
b) Maybe 10 max
c) Heating oil (aka kerosene)
d) by that I meant brushing out grinding dust etc and bleeding supply pipe after it ran out of fuel

All good now again though.

 

[rcx132]

Another update. The two latest pumps, which are a different brand, have also failed. So that's six pumps dead now. I ditched the kerosene and put in fresh pump diesel and the heaters have been going a week now. The kero was very old, reclaimed from a decommissioned tank. It had been properly filtered and I was told it would be fine. Guess not. It's nice to have a warm workshop again.

 

[not done it yet]

mostly independent with separate blocks, pumps, exhausts etc, but sharing a fuel tank and power supply.

I ditched the kerosene and put in fresh pump diesel and the heaters have been going a week now.

OK, so it wasn’t the first of the common items, it now appears it was the second.

Glad it’s fixed (hope they continue to work) - but an expensive fix all the same.

 

[Farside]

Another update. The two latest pumps, which are a different brand, have also failed. So that's six pumps dead now. I ditched the kerosene and put in fresh pump diesel and the heaters have been going a week now. The kero was very old, reclaimed from a decommissioned tank. It had been properly filtered and I was told it would be fine. Guess not. It's nice to have a warm workshop again.

I've read mention from various sources that plain kero should really be dosed with a bit of oil to keep the pumps happy.

 

[dobbslc]

Another update. The two latest pumps, which are a different brand, have also failed. So that's six pumps dead now. I ditched the kerosene and put in fresh pump diesel and the heaters have been going a week now. The kero was very old, reclaimed from a decommissioned tank. It had been properly filtered and I was told it would be fine. Guess not. It's nice to have a warm workshop again.

Is the power supply common to both pumps? If so I'd be taking a look at that incase it's over or under supplying them.

 

[JOEPRO]

I've read mention from various sources that plain kero should really be dosed with a bit of oil to keep the pumps happy.

FWIW I run my China heater on pure Kero and it runs for 10 hours at a time with no issues at all.

 

[Farside]

FWIW I run my China heater on pure Kero and it runs for 10 hours at a time with no issues at all.

The pumps obviously vary.

 

[JOEPRO]

The pumps obviously vary.

It's not as simple as that I'm afraid.

We are referring to a case of repeated pump failure. The causes can be for example:

Wrong ID fuel pipe or pipe collapse/ kink
Dirty or clogged pipe up tube/ filter
Poor fuel quality or other fuel contamination
Overvoltage or other current supply to pumps

I think the actual fuel itself plays a small part in it to be honest.

 

[nickk]

Could there have been a power surge causing faults?

 

[not done it yet]

The pumps obviously vary.

So can the kerosene fraction. There is more than one ‘grade’.

The lower the average carbon chain length, the less lubrication it offers. Likewise, lower sulphur content will also reduce the lubricity.

Could there have been a power surge causing faults?

Very unlikely - to the point of impossibility, I would suggest. Any power surge would affect (or be absorbed by) the power supply, not the DC usage. If it did, the ECU or controller would have been blown, I would expect, not the fuel pump.

 

[jsf55]

Does the filter you have fitted actually filter down small enough, i'm thinking 100 micron ?

 

[DAPPH]

I found by accident just after I installed my heater in Jan this year as a 12 volt supply that if the battery charger is on and the battery is getting charged with the charger supplying a fraction over 15 volts the heater shut down as an over voltage fault . It won't re start in that fault condition either , So I switched off the charger , left the battery to settle to 13.8 volts and it restarted immediately . Re the fuel pumps they do take in air it allows the piston to slide back to the bottom of the lift cycle by gravity . If there was no air you'd get a hydraulic lock . Next time you fire up your heaters take a few minutes to observe the out put side of the pump and you'l se a tiny air bubble every four or so seconds in the fuel line.

Another thing is cold fuel .. most fuels have a percentage of water in them , ice starts to form at 3 oC so if the pump is laying too horizontal or flat angled and the moisture in the fuel is thick enough just before 3 oC the piston will not fall back down to bottom of the pump stroke under gravity , hence the success of the heated pump ... a switched on 7 watt CFL bulb or black lamp vivarium ceramic heater bulb in a batten holder a few inches below the pump should help stop this happening in colder weather.
Though you might find enclosing this heater bulb and pump iunit s needed if we get in to the serious minus 18 oC or greater temperatures as it will also reduce cold air movement in the area of the pump ..

 

[DAPPH]

It's not as simple as that I'm afraid.

We are referring to a case of repeated pump failure. The causes can be for example:

Wrong ID fuel pipe or pipe collapse/ kink
Dirty or clogged pipe up tube/ filter
Poor fuel quality or other fuel contamination
Overvoltage or other current supply to pumps

I think the actual fuel itself plays a small part in it to be honest.

One thing not mentioned so far is that if the cap on the fuel tank is not breathing you can develop a partial vacuum in the tank as the fuel is consumed , once it gets to the trip point you heater won't work.
My tank cap is lightly tightened then backed of 1/4 of a turn to stop this happening .