Seaward Stove Conversion
I converted my Seaward to propane last year. The conversion kit is available from Seward (about $120), which includes new jets, thermostat, oven burner control, etc. You will find the model number of your stove on the back and it helps when talking to Seward. I had to get back with them as my kit did not have the correct oven jet. Please note that changing from CNG to propane IS NOT the same as going from propane to CNG! You will need the correct oven burner control as the CNG control allows too much gas to enter the system. Some things to consider:
1. You must run a propane line directly from your propane tank (or locker if
you have one) to the stove. Common sense and all the regulations say it is a
very bad idea to have joints in your supply line as each joint is a hidden location
that can fail and put propane in your bilge. I mounted an aluminum tank on be
rail ($140) and ran a 30 foot line to the stove. I also have a propane heater
mounted on the bulkhead and have another 40 foot line running to that unit (lines
run about $70).
2. When installing propane you must have an external shutoff switch that can
be operated from within the cabin. I wired mine to the masserator switch as
I removed that unit some time ago (These begin at about $70 as I recall).
3. You will remove all of your CNG gear, which will allow for better access
to you engine compartment if your is mounted like mine was in the port lazzerette.
Once this gear was gone, I cut a much larger opening to the engine compartment
and this modification was one of the best things I have done to my boat! I found
the gas fitting from the CNG hose to my stove to be extremely tight and I had
to use a pipe extension on my cresent wrench to free it.
4. Re-plumbing the stove essentially requires that you completely remove the
stove as you will find it much easier to do the job if you remove the stainless
cover on the right side of the stove to get to piping for the gas and thermostats.
While doing this, I also removed the teak panel from behind the stove to snake
the propane hose in. I discovered a good sized cubby that someday I will figure
out something to do with. It appears a previous owner used it to store some
emergency sustanance (beer).
5. You should also install a propane detector. I purchased one from an RV seller
for about $50 and installed it at the bottom, starboard side of the cabin steps.
The unit I bought malfunctioned last fall after only four months of use. Don't
know whether it was too exposed to weather in the location I chose or what.
I wired the unit so it would come on when I switched on the propane.
As usual, the cost and complexity of this conversion is significantly higher that it would seem on its face (a generalizable truth regarding sailboat projects). The project itself is not rocket science, but does require some time and care. For example, I checked every one of my connections with soapy water to ensure against leaks. This required I hook the stove up to propane and testing it while the right panel was still off and unit was sitting on the fridge. It also requires you run lines up, around and through from your propane tank to the stove, which is no fun if you don't cut out the false floor in the port lazzarette. Would I do it again? Absolutely! as propane is so much easier to obtain and use in my area. I cannot imagine running my heater with CNG as the cost would be astronomical!
Charles Finn
Mighty Quinn #114