# How to convert a Nat. Gas water heater to Propane?



## Melensdad

Just curious, can a natural gas water heater be converted to run on liquid propane?

Is it just a matter of changing out the burner in the base?


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## thcri RIP

Melensdad said:


> Just curious, can a natural gas water heater be converted to run on liquid propane?
> 
> Is it just a matter of changing out the burner in the base?




No.  Most furnaces you can but water heaters for some reason are a different.  You would think you could just change out that burner and orifice but I know of no manufacturer that has that kit available.  I don't get involved much in our plumbing department but I do know when we do a house that we know will have to be changed in a few years we give the customer a used water heater to use and then when the change is needed they buy a new one from us.  This is done mostly in new construction projects that start out as LP and then the local gas is expected to come in a few years later.


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## Melensdad

Hmmmm. . . that seems odd.


Any experience with SOLAR HOT WATER HEATERS that have either gas or electric back up?  

They seem to have 2 or 3 roof panels and then have either a gas or electric back up for cloudy days.  I'm curious how they work in the northern half of the US.


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## bczoom

Bob,

Isn't propane more expensive to run?  _Do I assume correctly that you're considering this option should there be an interruption in NG?_

I too am considering propane to augment my electric hot water.  My plan is to plumb in the propane hot water tank in parallel with the electric.  A couple valve turns, flick off the ele. breaker and fire up the pilot light on the propane and it's off of electric and running on propane.  _The only reason it's not done already as it's going to be a bit of a chore at my house to do the exhaust vent.  Being all electric, I don't have an exhaust stack anywhere._


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## Melensdad

Yes, propane is more expensive.  But if I can actually get off the grid it will require some combination of solar PV panels for electricity, plus solar hot water collection, and then some sort back up heat which would be either propane, natural gas, or wood.  Just trying to think through all the alternatives, not sure which way to go with parts of the system.


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## thcri RIP

bczoom said:


> Bob,
> 
> Isn't propane more expensive to run?  _Do I assume correctly that you're considering this option should there be an interruption in NG?_
> 
> I too am considering propane to augment my electric hot water.  My plan is to plumb in the propane hot water tank in parallel with the electric.  A couple valve turns, flick off the ele. breaker and fire up the pilot light on the propane and it's off of electric and running on propane.  _The only reason it's not done already as it's going to be a bit of a chore at my house to do the exhaust vent. * Being all electric, I don't have an exhaust stack anywhere*._




Can you go out the side of the house with a Power Vented PVC water heater?  Very seldom do I see a house that it can't be done.


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## thcri RIP

Melensdad said:


> Yes, propane is more expensive.  But if I can actually get off the grid it will require some combination of solar PV panels for electricity, plus solar hot water collection, and then some sort back up heat which would be either propane, natural gas, or wood.  Just trying to think through all the alternatives, not sure which way to go with parts of the system.



Propane is more expensive and pricing from year to year is extremely unpredictable.  Propane is also more dangerous in the fact that when there is a leak it is heavier than air and it sits in your lower level until a source of ignition is created.  I have seen LP go from $1.50 a gallon to $3.00 a gallon in one winter.  Weather can affect the pricing and what the farmers used to dry their crops.  Right now at least in our area it is on the low end.  Our house we are in right now was LP as there was no Natural Gas in the street.  A year later I was able to convert and we dropped our heating by more than 50%


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## muleman RIP

Throw in a propane boiler and an indirect water heater. Set it for cold start and tie in a coil in your air handler. All the heat and hot water you will ever need. As cheap as they are and the little bit of fuel they run when not heating the house it is the best setup for cheap hot water. I have been running mine for 6 years now.


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## thcri RIP

muleman said:


> Throw in a propane boiler and an indirect water heater. Set it for cold start and tie in a coil in your air handler. All the heat and hot water you will ever need. As cheap as they are and the little bit of fuel they run when not heating the house it is the best setup for cheap hot water. I have been running mine for 6 years now.



My system is of a Natural Gas Boiler with a Water Maker.  The boiler does my domestic hot water and all of my wirsbo.  I have two forced air furnaces to heat the rest of the house and do all of the air conditioning.  My water heater tank is 80 gallons and as fast as the recovery is with the boiler you can't run it out of hot water.  The hot water is the primary so it the water heater needs heat my wirsbo backs off until the boiler can be freed up again.


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## muleman RIP

I think I set my priority for the coil in the air handler.Would have to climb up and look at the relay box to be sure.


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## thcri RIP

muleman said:


> I think I set my priority for the coil in the air handler.Would have to climb up and look at the relay box to be sure.




In a forced air system probably right.  Wirsbo is a slow heat and can handle having the heat taken away from it for long periods.

The wirsbo in my garage I can turn it off in the winter and in three days the temp is still pretty good in it.


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## tommu56

bczoom said:


> Bob,
> 
> Isn't propane more expensive to run?  _Do I assume correctly that you're considering this option should there be an interruption in NG?_
> 
> I too am considering propane to augment my electric hot water.  My plan is to plumb in the propane hot water tank in parallel with the electric.  A couple valve turns, flick off the ele. breaker and fire up the pilot light on the propane and it's off of electric and running on propane.  _The only reason it's not done already as it's going to be a bit of a chore at my house to do the exhaust vent.  Being all electric, I don't have an exhaust stack anywhere._



Put them in series electric first gas second  and it is automatic keep pilot on to keep the tank from getting cool and producing condensation and rusting gas heater out, it will pop on occasionally but not much .

tom


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## bczoom

Tom,

If they're in series and the gas isn't on in the 2nd tank, the water will be relatively cold if it has been sitting overnight.  Makes for a long wait before getting hot water in the morning as it needs to get it from the ele. tank cycled into the cold water in the LP tank.


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## BigAl RIP

Bob ,
 If your existing tank is more than 5 years old I would just go buy a Propane unit instead of putting money into a 5 year old used unit . The cost of trying to convert would not be worth it . JMO


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## Doc

30 years ago you could convert from gas to propane by simply changing the orifice.  I suppose modern technology has enhanced the burners to where you need gas specific burners for whatever you are burning.  Sometimes we take two steps back before we step forward.


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## muleman RIP

It has more to do with induced draft instead of chimneys. The blowers and sail switches and vent pipe are all sized to coordinate with each other at a specific firing rate. The old days with natural draft chimneys almost always had excess draft and could draw varying fire rates. They also suffered from excess standby heat loss for this very same reason. I hold national certification from both NORA and NATE and it all plays a part in the efficiency of the appliance. There are also NFPA regulations that are a factor in all this to insure folks wake up each morning and don't go boom.


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