more heater problems help needed :O(

[Nige123]

Hi I'm new here & would like to know if anyone has had the same problem as I have with a Mikuni MX40 boiler????

 

all has been fine for most of the winter then the heater plug went...

no big deal just fitted a new one & it run fine for about a week...

 

the plugs had a black & almost metalic like carbon build up running down one side of them, & now only last about an hour or so before before the coil burns out & snaps (

 

at first I thought I may have a deisel problem so I have fitted a "boiler only" tank & filled it with new deisel & the same thing happens so it can't be a deisel.....

 

so any help would be good before I get the heater in bits all over the place.........

 

 

if only the boat had a back boiler fitted to the woodburner I would be a happy man.....

[GUMPY]

Hi I'm new here & would like to know if anyone has had the same problem as I have with a Mikuni MX40 boiler????

 

First question did you clean the air holes in the glow plug boss?

 

If not, refering to this diagram:

 

http://www.mikuniheating.com/index.php?p=p...3&parent=22

 

remove glow plug (6)

remove diesel feed to glow plug boss

remove two screws that hold boss to body of heater (34)

remove boss, it will be tight.(5)

in the boss are two 2.5-3mm holes that swirl air round the plug and keep it clean

using a 2.5mm drill bit between thumb and forefinger clean out these holes.

Re-assemble with new gasket and new disc spring (7 and 31)

you may get away reusing the gasket and disc spring it depends on how old they are.

If this is not done EVERY time you change a plug then the unit will blow the plug in a short time.

 

Hope this helps

 

Julian

[smileypete]

Hi I'm new here & would like to know if anyone has had the same problem as I have with a Mikuni MX40 boiler????

 

all has been fine for most of the winter then the heater plug went...

no big deal just fitted a new one & it run fine for about a week...

 

the plugs had a black & almost metalic like carbon build up running down one side of them, & now only last about an hour or so before before the coil burns out & snaps (

 

at first I thought I may have a deisel problem so I have fitted a "boiler only" tank & filled it with new deisel & the same thing happens so it can't be a deisel.....

 

Hi,

 

See these threads:

 

http://www.canalworld.net/forums/index.php...=10099&st=0

http://www.canalworld.net/forums/index.php...=10822&st=0

 

cheers,

Pete.

Edited March 24, 2008 by smileypete

[Nige123]

First question did you clean the air holes in the glow plug boss?

 

If not, refering to this diagram:

 

http://www.mikuniheating.com/index.php?p=p...3&parent=22

 

remove glow plug (6)

remove diesel feed to glow plug boss

remove two screws that hold boss to body of heater (34)

remove boss, it will be tight.(5)

in the boss are two 2.5-3mm holes that swirl air round the plug and keep it clean

using a 2.5mm drill bit between thumb and forefinger clean out these holes.

Re-assemble with new gasket and new disc spring (7 and 31)

you may get away reusing the gasket and disc spring it depends on how old they are.

If this is not done EVERY time you change a plug then the unit will blow the plug in a short time.

 

Hope this helps

 

Julian

 

 

 

 

 

 

 

many thanks Julian I didn't clean out the holes so will try that as soon as I get some more plugs from ebay (about £15.00)

[Cinimod]

many thanks Julian I didn't clean out the holes so will try that as soon as I get some more plugs from ebay (about £15.00)

 

FYI - I got a couple of Beru GH408 sparkplugs.co.uk for 9.55 each + del & Vat (total bill £25.03 for 2)

 

They seem to do the job as well as others...

 

HOWEVER... still having the ongoing fight with trying to get the thing to work.

 

It is either coming up with the lights flashing saying overheating or tripping the 12v breaker on our panel...

 

Is it possible that the water pump is not pumping any water through it?

How can I check, how can I make sure it is full of water!

 

Thanks for your help.

 

Dominic

[GUMPY]

FYI - I got a couple of Beru GH408 sparkplugs.co.uk for 9.55 each + del & Vat (total bill £25.03 for 2)

 

They seem to do the job as well as others...

 

HOWEVER... still having the ongoing fight with trying to get the thing to work.

 

It is either coming up with the lights flashing saying overheating or tripping the 12v breaker on our panel...

 

Is it possible that the water pump is not pumping any water through it?

How can I check, how can I make sure it is full of water!

Ok

The water pump is the first thing to fire up and you should hear it whine.

 

With the system off and cold:

 

just below the water outlet ( on the top of the heater) is a 1/4inch square head plug, this is what thay laughingly call a bleed screw, be very carful as its real easy to strip the threads, remove it you should get water out of there and no air.

You should also have a header tank that is higher than the heater this should be half full.

In an ideal world the heater should be the higest point apart from the header tank hence the bleed screw. If its not then you should have a bleed fitting at the higest point.........

Check all the radiators are free of air using the bleed screws on them.

 

One final point which is missed by many you normally cannot just run a calorifier off the mikuni as the OP is to high and there is not enough heat transfer so it overheats, you must have at least one radiator on as a heat leak..................

 

Julian

[Tony Brooks]

Ok

The water pump is the first thing to fire up and you should hear it whine.

 

With the system off and cold:

 

just below the water outlet ( on the top of the heater) is a 1/4inch square head plug, this is what thay laughingly call a bleed screw, be very carful as its real easy to strip the threads, remove it you should get water out of there and no air.

You should also have a header tank that is higher than the heater this should be half full.

In an ideal world the heater should be the higest point apart from the header tank hence the bleed screw. If its not then you should have a bleed fitting at the higest point.........

Check all the radiators are free of air using the bleed screws on them.

 

One final point which is missed by many you normally cannot just run a calorifier off the mikuni as the OP is to high and there is not enough heat transfer so it overheats, you must have at least one radiator on as a heat leak..................

 

Julian

 

I have seen such a heater without a header tank but with two "accumulators" acting as expansion vessels and I suppose a supply of water as per combi-boilers. In this case there was no pressure showing on the pressure gauge so I assume there was no "store" of water in the "accumulator". Unfortunately it did not appear to have a "filling loop" so forcing water into the system would involve external connections.

 

I mention this just in case the system in question has been plumbed like this and it is out of water.

[Cinimod]

Just below the water outlet ( on the top of the heater) is a 1/4inch square head plug, this is what thay laughingly call a bleed screw, be very carful as its real easy to strip the threads, remove it you should get water out of there and no air.

You should also have a header tank that is higher than the heater this should be half full.

Thank you VERY much - will try this...

We do indeed have a header tank, with plenty of water...

The hose from the calorifier to the heater is very hard, I wish there was some way to put a window, or a spinny thing in it so you could see the water is flowing.

 

We also have 4 rads so that should be fine, and I checked that they are not bypassed by the valves under the stairs!

[Cinimod]

Ok

The water pump is the first thing to fire up and you should hear it whine.

 

With the system off and cold:

 

just below the water outlet ( on the top of the heater) is a 1/4inch square head plug, this is what thay laughingly call a bleed screw, be very carful as its real easy to strip the threads, remove it you should get water out of there and no air.

You should also have a header tank that is higher than the heater this should be half full.

In an ideal world the heater should be the higest point apart from the header tank hence the bleed screw. If its not then you should have a bleed fitting at the higest point.........

Check all the radiators are free of air using the bleed screws on them.

 

One final point which is missed by many you normally cannot just run a calorifier off the mikuni as the OP is to high and there is not enough heat transfer so it overheats, you must have at least one radiator on as a heat leak..................

 

Julian

 

I get a wait, I guess while the glow plug heats, then whining, then clicking (I think this is the fuel pump?)

 

BUT I think I have just about had it with this thing.. tried the suggestions, it appears to be firing up for about 3 minutes, then stops... it is not tripping the fuse now, which is an improvement, but stopping is not particularly good... Think it is still saying it is overheating...

 

This happens when the water in the calorifier is cold, or hot (the engine heat it too..)

Just wondering, as the engine is heating the calorifier, and the pipework from the Mikuni runs through the calorifier then off to the radiator - does it sound feasible to add another pump into that circuit to pump the water round the rads as they should draw heat from the calorifier?

 

The next step I think, is to bin the Mikuni and get a Squirrel with a back boiler... any suggestions on where is good to source those, and get it fitted?

Also will this supply hot water to the rads and the calorifier too, so that we would not need to run the engine too much?

 

Thanks for all your help...