Propex heaters

[diesel falcon]

ermm it,s in the cupboard right in prow of the boat next to the chain locker!! and the outlet is where the sterio speaker was

[quo vadis]

ermm it,s in the cupboard right in prow of the boat next to the chain locker!! and the outlet is where the sterio speaker was

At head height then Trev just the job!!!!

[senator]

the unit can go anywhere you can get gas to it and mount the exhaust fitting within 1m on the hull but as MBA Marine has already said you can not mount any heater, including the diesel fired ones in a petrol engine engine bay or any place that is not sealed from it.

they work exactly the same as the diesel versions, air for heating is heated by a heat exchanger within the unit, the combustion side is completely separate, air in and exhaust out for combustion are through the same skin fitting which can not be mounted more than 1m from the unit, this usually sites the unit as it is a good idea not to put it under water. it is better if the air from the cabin is recirculated through the unit as that has already been heated once.

You don't need much room round the unit but the exhaust does get hot so you will want to lag this with suitable insulation if you put it anywhere near something heat sensitive. You obviously need as much air in to the unit as it is going to put out into the room but if you have put it somwhere sealed you can put the same ducting on the air inlet as outlet, and pull it from the cabin.

[mbird]

Have never looked at these heaters and have diesel heating anyway but, out of interest, being gas does not it increase humidity in the boat? Or is it much like diesel with the burner in the engine bay and a fan circulating the heat?

The Propex works exactly the same way as a Webasto etc in that the gas is burned to heat a heat exchanger and the exhausted outside the boat. The heating air is drawn over the heat exchanger by the fan and then circulated to the outlets. Consequently there is no increase in humidity in the boat, and all combustion gases are totally separate from the heating air.

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[mbird]

Oops, just noticed Ian has already answered that!

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[DaveS]

I have Propex 1800 on my boat, and it doesn't work.

More specifically, it starts up with the normal 30 second fan blast to clear the combustion chamber, but then won't ignite, and the LED on the control panel flashes a five pulse sequence, which = failure to ignite.

A Google search revealed that it is a very common problem, and usually due the failure of a small fan on air intake side of the balanced flue.

Apparently, if the unit isn't used regularly, this fan sticks, and it doesn't spin, the electronics see this as a fault condition, and will not let the unit ignite.

Having spoken to Propex, they are very aware of this fault, and suggest blowing up the combustion air intake with a air-line, to free the fan of any cobwebs or such like.

I tried tried this several times, to no avail, and after speaking with Propex again, they told me that because of this problem, they now use a different ignition module.

The new module can be purchased from them for something like £50.

Before I buy one, I'm going to open the unit, and see if I can free the fan.

Dave

[mbird]

Hi Dave

I had a Propex on my last boat, which had similar symptoms once after I ran out of gas. To clear it the manual told me to turn the switch on then off again twice within 2 seconds. Took me ages to find that in the manual! I'm not sayin gthat is the fault you are experiencing, but might be worth a go!

[diesel falcon]

I blow mine with my mouth, one good blow and then a suck on both the inlet and exhaust , and usually it,s good to go, take the hoses off at the skin fitting mine had water in after windy very rainy days we,ve had this winter

[DaveS]

Your comments seem to align very nicely with the multitude of other Propex users, in that it is a VERY common problem.

When the boat was out of the water, I removed the baffle plate from the flue fitting on the outside of the hull, stuffed plastic pipe up both the intake and exhaust, and blew for all I was worth, to no availl.

I then tried it with a high volume dinghy inflator, but again no joy.

So if it is case of the fan sticking, it is well and truly stuck,

I tried just about every sequence of turning it on and off, but no go.

Basically, its a 'crap' design, which is supported by the fact that Propex probably had so many people contacting them about this problem, they have changed the design of the ignition module.

I will take the ingition unit out, and see if it can be sorted, but if not it looks like its £50 for a new module.

On the basis of this problem, if the re-designed module doesn't sort the problem, then I certainly would not recommend Propex.

Dave

[diesel falcon]

Another problem i had was a loose cable(earth) which is attached to the outer burner surface,had to put a replacement screw in as the original wouldn,t tighten ,i ve run mine for 4 years and i suppose it,s failed 4 times, twice when new ,board once which was replaced free/exchange,and the rest starting after a long lay off,i now give it an occasional burst in summer

[DaveS]

Ok, problem sorted and the Propex 1800 is now working

 

Went down to the boat today, to have one last attempt to get the unit to fire up, before ordering the new design of ignition module from Propex (circa £50).

 

When the boat was out of the water, I had removed the 'baffle plate' on the 'through hull' balanced flu, and blown (via mouth) up both the inlet and exhaust pipes, as suggested by Propex, to try and free the combustion air input fan. This didn't work, so I connected the pipe from a dinghy inflator pump, and tried blasting it with this. Again no joy.

 

Today, I disconnected the combustion air input pipe from the heater, and connected the pipe from the dinghy pump to the inlet spigot. With the wife up in the cockpit working the pump  , and me laying in the bilge holding the pipe in-place, to maintain a good seal, we gave it a good blast  .

 

Fired up the heater, and 'bingo' it worked  .

 

I then reconnected the pipe from the balanced flu, while the heater was running, and it stayed running.

 

The moral of the story is, if you have a Propex heater, with the earlier type of ignition module (Propex have now changed the design because this problem), don't leave the unit unused for extended periods. Give it a run now and then, even in a heatwave  , or the problem will just keep on happening.

 

Dave

[mbird]

Glad you got it all working Dave!