Propane furnace "POOFS" several times when starting heat cycle
Propane builds up in the heat chamber and when igniter turns on it "poofs" or has a mini gas explosion several times before the burners settle down and continue to burn correctly. Furnace does work correctly after several poofs. Burners were removed and cleaned and are in good shape, ignitor rod can be seen turning red, Could this be a regulator problem? thanks, cliff
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Re: propane furnace "POOFS" several times when starting...
I'm not sure how you are going to solve this, as propane's relative gas density is 1.55 times that of air, causing the gas to "pool" up in the bottom of the ignition chamber... After you are hearing the "poofs", the chamber is probably warmed up and the convection of the column of air rising then prevents the pooling of the gas towards the bottom. Hence the poofing goes away. Is there a pre-warmer or something that you are missing?...
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You didn't mention how old your oil furnace is. But, if it's got some age on it and it's hasn't been serviced annually, the heat exchanger may very well be cracked. But, before you decide to tear it apart and make it a DIY project, you may well want to half a qualified service technician take a look at it. Because, replacing the heat chamber, even if you do it yourself, may be more expensive in the long run, than replacing the furnace with a more efficient, up to date model.
Don't forget, most oil furnaces can be converted to gas (either Natural Gas or Propane) which burns cleaner & hotter than oil. And cost less to operate. I did it in one of my previous homes and was glad I did. My annual heating cost decreased almost 30%. That savings paid for the conversion in 3 years.
First, for those of you who might not know,
"What is a flame sensor?" A flame
sensor is a safety device. When your furnace's main burners ignite (light Up)
the flame sensor picks up the heat from the furnace's main burning and says,
"YES," and sends a signal back to the main furnace control board saying that it
is OK to let the main burner stay on. Or if the main burners do not ignite, the
flame sensor does not pick up the heat and says, "NO" to the main control board,
Shut That Gas Valve and Main Burners Down! Thank God we have safety controls
like the flame sensor. Most of the time, after turning your furnace's power off,
you may clean the flame sensors with light sand cloth, emery cloth or steel
wool. Reinstall the flame sensor and you are back in business! Over the years
flame sensors can build up a light coating of burned-in dust and dirt. This
insulates the flame sensor so that it doesn't sense the heat of the flame well
enough, so by cleaning it you have almost restored it to its new condition.
Seldom, but sometimes they do go out completely.
Actually yes! You can install electric elements in the plenum that turn on by your thermostat. The convection blower from the furnace can be used. You can also install a heat pump system that will give you both heat and air conditioning.
It sounds like you have a possible hole in the heat exchanger. Turn the heat off and turn the fan on. If you feel any air coming back out of the heat exchanger, you have a hole. A yellow flame is not a good sign. I would even consider having a service professional come out and take a look.
69,000 btuh is adequate for a 12-1400 square foot house.
Otherwise, your thermostat simply tells the furnace to cycle on/off.
If it calls for heat and does not come on, the problem is with switches and relays within the furnace.
Your setting the temp higher only causes the other parts to keep trying until they finally light and heat.
This is based on your information saying it will cycle on and blow cool air--not hot air.
You will have several temperature variations from floor to ceiling.
You probably have ceiling vents as well.
You need a technician to verify the rollout switches, fan relay, inducer fan etc. if the furnace is not firing everytime you call for heat.
Make sure fan relay is wired correctly (G) wire. Ensure the fan on therm is not on, it should be on Auto or off.
If your furnace is short cycling because it has to keep heating your home, the delay in the control board may be staying on to compensate for the exchangers getting hot. If it heats normally, then put your attention to your thermostat.
Set the heating system on aux heat only. Fan should not be on, if it does stay on after a heating cycle, see if the furnace is heating normally, and reaching temp as desired before the heat comes off. Then check the therm wiring, pull the face of the therm, disconnect green wire (fan) and try the heating again.
Honeywell makes an electronic ignition conversion kit. (White rodgers also has one but it uses a mercury switch which can be expense if it goes bad). A good service man can install the "Honeywell Y86 Universal Intermittent Pilot Retrofit Kit". This is a "complete" kit for converting a standing pilot system to electronic ignition. It includes a new gas valve, ignition cables with connectors. ignition module and a pilot assembly. It does not include pilot tubing (pilot tubing is cheap). This kit also comes equipped for either natural gas or propane. Your heating guys probably don't know about it because they are to young and not familiar with the old days. Or they just don't care and would rather sell you a furnace. I think that they just don't care. I live in Ohio I just opened up the "new" Johnstone Supply catalog. This part is "not" outdated its on page 450. Do not let these heating guys buffalo you into a new furnace. You are to smart for that! If you weren't you would have believed them and bought something you don't need. Instead of researching on the internet.
The bad news is this kit lists for $456. plus labor.