Lighting a Pilot that is Electronic Ignition – This is one of many questions we get by email.
Lighting a Pilot that is Electronic Ignition Comment: Thank you for your interesting discussion of pilot lights vs. electronic ignition. I may have to replace my gas water heater soon and am weighing the options. Although I understand that electronic ignition is more efficient, I worry about not having hot water during a power outage. A number of years ago we had an ice storm and the power was out for almost a week. My gas water heater still worked as did my gas stove, and that really made a big difference. That happened when the temperature outside was in the 20’s (F). Is there any way to light a water heater with electronic ignition by hand? Or is it completely dependent on electricity? Thanks for any information you can provide. (more…)
Gas Manifolds – The furnace gas manifold connects the valve with the main burners and it is important that the proper pressure be present inside the manifold for proper combustion. Manifold pressure is different from natural gas to liquid propane and this pressure needs to be set with a special instrument which the HVAC installer or HVAC start-up technician should have. The manifold pressure should be set according to the furnace manufacturer’s instructions and is done by an adjustment on the regulator and valve as noted in the valve section (see gas furnace components). The setting will depend on the type of fuel, natural gas or LP, and the manufacturers instructions.
Gas Furnace Troubleshooting and Repair – Flash Codes . In the extreme cold weather there is nothing worse than losing your heat. Here are some tips for checking basic problems where the average person can make a quick fix. Hopefully you do not have to suffer while waiting for the HVAC repairman.
What you will learn from How to Test a Thermocouple with a Multi-Meter
- How not to guess if the thermocouple is bad
- Step by step procedure for testing a thermocouple with a multimeter
- What reading you should get if the thermocouple is good
- Lots of resource and related links to help you learn more
How to Test a Thermocouple with a Multi-Meter? So you have found the pilot light will not stay lit when you try to light the pilot light. You know you have gas and everything seems to be fine so what is the problem?
Trane Gas Furnace Efficiency Factors – This is a Trane gas furnace. It is also called a Trane 90 plus gas furnace because it offers efficiency levels up to 90 percent plus AFUE (rating). Gas or oil furnaces generally cannot achieve efficiency at 100% because of impurities in the fuel including moisture. This is the reason why no fossil fuel furnace sold has a rating of up to 100%. This biggest impurity in many fuels is moisture which is difficult to remove because it is in the distribution and storage places where the fuel is distributed and stored. If these impurities were removed from the fuels before they were introduced to the furnace the cost of the fuel would be much higher and the cost to benefit ratio would not be effective. (more…)
You can see the rust holes up near the sheet metal plates in this heat exchanger that made the occupants sick
Gas Furnace Heat Exchanger Failure – Richard, a technician just departed my house after looking at my gas furnace. My mom thought she smelled something so we called the furnace company we usually call when we need furnace maintenance to check it out. He told us our heat exchanger in our furnace failed. I asked him how much it would cost to fix and he told me his service manager would call me with a price. I just got off the phone with the service manager and he said the furnace is still under warranty but we would have to pay for labor. The new heat exchanger is covered under the warranty. He said the labor cost would be $850.00 to replace the heat exchanger. The furnace is over 7 years old and the heat exchanger has failed? Isn’t this a major component of the furnace and if it failed in 7 years won’t the new replacement heat exchanger have this issue in another 7 years? What is supposed to be the lifespan of a furnace? If so isn’t it a better decision to just replace the furnace altogether? And why would I want to buy this brand again if it failed so soon? We are cold right now but going to get some portable electric heaters. We need to make a decision soon. Thank you and I look forward to your answers. Jenna (more…)
How a Gas Furnace Works . Richard, Can you please explain to me in basic terms how a gas furnace works? I have a standing pilot gas furnace if that helps you better.
This question is closely related to my article on the Gas Furnace Sequence of Operation. Each type of gas furnace works differently. Therefore, the sequence of operation or how the gas furnace works will work differently for each gas furnace type. Since you have a standing pilot gas furnace it will work differently from an electronic ignition gas furnace. (more…)
Gas Furnace Troubleshooting Techniques . Electronic ignition for gas furnaces are the modern way for furnaces to light the main burners. Furnace technology has evolved from the standing pilot gas ignition systems. These furnaces continue to be used today however there are less standing pilot furnaces used today than yesterday. When troubleshooting a system it is important to know which type of ignition system the furnace uses. (more…)
Two-Stage Gas Furnaces
2-stage gas furnaces are ever increasing in popularity among HVAC manufactures of gas furnaces. The product lines are ever increasing from single stage gas furnaces to two stage gas furnace. The reasoning is that the two-stage gas furnaces are more efficient than the single-stage furnaces. This is according to tests performed using the Department of Energy’s test guidelines in accordance with testing AFUE ratings for gas furnace. Is this true and is the test of gas furnaces correct in making the claim that the two-stage is more efficient than the single stage gas furnace? Before we make any claims to about the validity of the test we must first observe where the origin of the DOE guidelines for testing heating appliances come from. These test guidelines come from ASHRAE or the American Society of Heating, Refrigerating, and Air Conditioning Engineers. The current standards used to determine AFUE or Annual Fuel Utilization Efficiency was written and adopted by DOE in 1993 from multiple revisions dating back to 1982 where the origin of AFUE was made. The tests are applicable to gas furnaces/boilers, oil furnaces/boilers for determining AFUE.
Dangerous Cracked Heat Exchangers in Furnaces . Everyone wants heat when old man winter arrives in the fall. Many times we take it for granted. When the temperature falls all we have to do is go to the thermostat and turn the heat on. Usually, this is not a problem. We turn the thermostat on and the heat comes on. When we first turn the furnace on we have a slight burning odor which comes from the system. (more…)