I wanted to post this because many people are telling me that they are sucking on the pressure switch tubing to test pressure switch operation. I have heard from other forums that you should not suck on the pressure switch to test it because this can damage the diaphragm inside the pressure switch. It would be best to use a manometer or test with a volt meter like we advise on the following page: https://arnoldservice.com/how-to-test-and-troubleshoot-gas-furnace-pressure-switches/ I wanted to pass this along so others will not damage pressure switches. Please feel free to comment below.
I remind myself of a terrible experience I had several years ago when I brought my desktop computer in from a cold car, plugged it in and fried the mother board! I found out the hard way that it is always a good idea to allow an electronic part like control boards, pressure switches, televisions, laptops, etc. to warm up to room temperature before applying power. If you bring anything in from the cold outdoors into a warm home, condensation (water) will form on the part. We all know that water is a conductor. We can see why so many electronic parts can get destroyed if we do not allow them to warm up before applying power. I would strongly suggest that we allow the electronic parts and devices to sit for a couple of hours for warm up. This allows time for the water condensation to evaporate before applying power. I hope this will save you and others from problems.
Question: Hi, I have a BDP/Carrier furnace from 1987. The burners will light and run for about a minute or two, but within a minute after the blower turns on the burners and pilot go out. If I remove the cover to the blowers the burners will stay on and heat the house. I checked to make sure the air intake vents in the house are not covered. Any suggestions?
Answer: Hi Darren! Great question! This sounds like the furnace is probably over-heating and going off on limit. I would suggest that the next time the furnace gas goes off prematurely that you check the limit with a volt meter to see if the limit is the problem. You might need a new limit or more than likely the limit is doing its job by cutting off the furnace to keep the furnace from getting too hot. Over-heating of the furnace can be caused by as you have already checked some of the registers being blocked or turned off. Over heating of the furnace can also be caused by a dirty filter, dirty blower wheel, slow blower motor, (might need a new capacitor) stopped up or blocked air conditioner evaporator coil or the gas valve gas pressure being set too high. I would suggest checking the easy causes first like the filter, dirty blower wheel or have the capacitor on the blower motor checked. Best of luck in finding and fixing this problem.
Question: In May I started to have some problems with my outside ac unit. My fan stopped running but I could get it back running by spinning the blade when it hmmmmmed. Blade was easy to spin Called an AC Company to see what was wrong They said the fan motor was bad and put in a new fan motor and oval capacitor.
But didn’t replace the dual capacitor said it didn’t need to be replace it was good. Ran good and cooled down the house good for about a mouth or so but started having the same problems. My fan stop running I could get it back running by spinning the blade when it hmmmmmed. Blade was easy to spin, but motor was hot to the touch
Ac company came out again said it was a bad new motor. Company put in a new fan motor and oval capacitor but didn’t replace the dual capacitor said it didn’t need to be replaced that the capacitor was good. Ran good and cooled down the house good for about a mouth or so but started having the same problems. My fan stopped running but it’s hard to spin now and takes a couple of tries to spin when it hmmmmms. The motor was hot to the touch. Now the fan motor won’t start to spin by me spinning it at all. It is too hard to spin. Note: The motor is still hot to the touch. What could be possible wrong with my unit? Why does my fan motor keep burning up?
Answer: Hi! I am so sorry to hear that you are having all these problems with your fan motor. There are several things that can cause a fan motor to go out prematurely. I will list some of them below then you can assess whether any of these might be causing your fan motor to go out so often.
1. Installing a universal fan motor that is not matched correctly with the right RPM or horsepower to power the fan blade. Motor not matched to the diameter and pitch of the fan blade. Motors should be matched (RPM, Horsepower, Amps) with the fan blades or it will over-load the motor and the motor will fail soon.
2. Having a fan blade that is off-balance and causes vibration to the motor and unit. A new balanced blade would be best.
3. Installing a fan motor and capacitor where the capacitor does not match the specs on the label of the fan motor. The fan motor capacitor should match the specifications on the motor label.
4. Installing a fan motor where lots of moisture is present like from a leaking gutter or down spout. Water pours on to fan motor when it rains or when snow melts.
5. Not having the rain shield installed (when required) or leaving drain plugs open where water and moisture can get into the motor. Some motors have rain shields to prevent water from getting into the motor. Many universal motors do not have rain shields, but have drain plugs that can be opened or closed depending on how the motor is installed, horizontal, vertical, shaft up or shaft down.
6. Improper wiring. Where the motor is not wired according to the label on the motor.
7. Improper rotation of the fan blade. With the fan blade spinning in the wrong direction the motor will not load and it will burn up over time.
7. Grass, weeds, plants or children that stick into the fan blade path and stop or impede the fan motor when it is running.
More than likely the HVAC company you had installed a universal fan motor. Many of these motors use an individual capacitor and this is why they did not hook into your existing dual capacitor. They probably are using the dual capacitor for the compressor only and the fan motor they installed has a separate single capacitor. I am just guessing. I am thinking that probably number 1 is probably the problem. That is why we mostly sell OEM fan motors so they will be matched with the fan blade and the customer has an easy time with the installation. If you would send your unit’s model number I will try to find out which OEM motor fits your unit. Our support email address is: email@example.com. We will be glad to try and help you out! Steve Arnold
Please comment below if you would like to add to this post or email us at: firstname.lastname@example.org
Problem: I have a bad igniter, is there anyway to light a gas furnace manually? My family is cold please help!
Solution in an Emergency Situation: An Emergency situation would be a situation where your furnace ignitor goes out in the middle of the night, on the weekend or holiday. It is Super cold outside and you need to get heat from your furnace to protect your family and the pipes from freezing. We have had many customers who are cold and without heat over the years on the weekends or Holidays. They do not want to wait on a service tech or wait on shipping for a new ignitor. They need heat as soon as possible. I feel very sorry for them being without heat when it is real cold out! I decided I would include this YouTube video on how to light a gas furnace manually on our website. Below we have a YouTube Video which shows how to manually light a furnace when the ignitor fails. I only provide this video because I do not want to see anyone be cold when they could actually have heat in their home. Changes in the video that I would make would be to: (1) use a long wooden match instead of the lighter. (2) Make sure the match is burning when the draft inducer comes on. You must make sure the burning match is sitting in front of one of the burners before the gas valve opens. The worst mistake would be to allow gas to come into the furnace and then apply the match. This could produce a mini-explosion or fire! (3) You should control the furnace On/Off using the electrical switch (like a light switch) usually located on the side of the furnace. This way you are not depending on someone else to turn the thermostat up and down and you have immediate control of the furnace. The match needs to be burning and sitting in front of one of the burners before the gas valve opens. Please remember the gas valve is only going to be open for 7 to 10 seconds and if the flame sensor does not sense the furnace flame then the gas valve will shut off until there is another cycle. Below we have a YouTube Video that shows how to Manually Light a Gas Furnace when you have a bad igniter. This video was made by Chris Swain. Thanks to Mr. Swain for making this informative video. I hope this will save you from having a cold home.
Please send us your furnace’s model number if you would like for us to use one of our online parts programs to recommend a replacement ignitor for your furnace. On Bryant Carrier furnaces we will need the product number. On Rheem Ruud we will need both model number and serial number. All other furnaces just the model number. Our email address is: email@example.com. Please click here if you would like to see the furnace ignitors we sell.
*Disclaimer: Arnold’s Service Company, Inc. assumes no liability for any incidental, consequential or other liability from the use of this information. All risks and damages, incidental or otherwise, arising from the use or misuse of the information contained herein are entirely the responsibility of the user. Although careful precaution has been taken in the preparation of this website’s information, we assume no responsibility for omissions or errors.
Below we have an Aprilaire humidifier 500 maintenance video made by HVAC.com. Many thanks to HVAC.com for making this informative video! This video shows you step by step how to perform the seasonal maintenance on your Aprilaire 500 Bypass Whole Home Humidifier. In the video it shows how to check the water feed tube, the strainer, the drain tube, the drain spud, the orifice, and the water panel. All of these are important parts that ensure your humidifiers performance and efficiency. Please click here if you would like to see the parts and supplies that we sell for the Aprilaire Model 500 series humidifiers. Please email us anytime if you have questions. Our email address is: firstname.lastname@example.org. We would love to help you out and have your business!
Below we have an Aprilaire Fan Powered Humidifier Maintenance Video made by HVAC.com. Many thanks to HVAC.com for making this informative video. This video will show step by step how to service your Aprilaire 700, Aprilaire 700M, Aprilaire 760, Aprilaire 768 fan powered humidifier. Please click here if you would like to see the Aprilaire humidifier parts and supplies that we sell for the Aprilaire model 700 series humidifiers. If you have any questions please email us anytime: email@example.com or comment below. We would love to help you out and have your business!
Problem: Hello, love the website and help that it offers. But I seem to be out of options with my furnace here. I have a Carrier HE furnace that is not even 3 years old yet. We have had repeated issues with the furnace running for 2-3 minutes, stopping, recycling and coming back on until desired temp is reach. Sometimes this will occur 3-4 times depending on reaching desired temp in the home. When I called a technician he came out and charged 170$ just to tell me my pressure switch was broken. And offered to replace it for another 150$(!). I ordered one myself and replaced it last weekend. Took me 5 minutes and switch was 60$. But, I’m still having the same symptoms. Sometimes the furnace will not even come on and we awake to a cold house. Other times it works just fine…??… it’s “buggy” as I describe it. I am getting a 3 to 1 LED code indicating pressure problems. But I have cleaned the water trap multiple times and there seems to be no issue. No water lines to or from are blocked. Exhaust is not blocked leading outside. Nor is intake. And again the pressure switch is brand new (supposedly). And I have also cleaned the flame sensor with newspaper (no steel wool). I don’t believe that is the problem. Seems clean. No residue on it. So, if you can offer any help please do! Cleveland is about to have sub zero Temps coming up this weekend! Chris
Answer: Hi! I am terribly sorry that you have encountered all these problems with your furnace. We have a furnace troubleshooting flow chart that I hope will help you out on the following page: Please click here if you would like to see our Gas Furnace Troubleshooting Flow Chart. I would start with making sure the thermostat is providing 24 volts between W and C terminals on the control board when the furnace cuts off. If you are getting a constant 24 to 28 volts AC to the furnace all the time between W and C when the furnace cuts off then this would eliminate the thermostat from being the problem. If the control board is correct in saying and showing that the pressure switch is the problem… then I would suggest looking at the things like you have already have, like the condensate trap and drain lines from the secondary heat exchanger. Please make sure the furnace is tilting forward slightly so the water drains out the front of the furnace. The installation instructions on these high efficiency furnace tells how many feet of vent pipe are allowed for venting. If the allowed vent feet are exceeded then you will have trouble with the pressure switch not staying closed. The 90 degree turns in the venting sometimes are calculated as 5 feet of piping. If you have exceeded the number of turns the furnace will not run right and the pressure switch will not work or stay closed. I remember one furnace I installed where I tried to use 2″ PVC for the venting and ended up having trouble with the pressure switch going off like your furnace is doing. I ended up having to tear the 2″ pipe out and install 3″ PVC vent. The venting is critical for these high efficiency furnaces to run right, to say the least! Some other things that cause furnace pressure switch problems are: (1) A restricted vent pipe (2) Too long of vent piping and too many turns which exceeds manufacturer’s recommendations (3) a stopped up condensate drain line if you have a high efficiency condensing furnace. (4) a dirty or stopped up draft inducer. The hole where the pressure switch attaches to the draft inducer could be stopped up with water, slug or dirty. (5) a slow draft inducer that might need a new capacitor or has slowed down. (6) someone has sucked on the pressure switch with their mouth or forgot to unhook the pressure switch from the furnace before using a vac on the furnace. Sucking on the pressure switch or leaving a pressure switch attached to furnace when vacuuming out the condensate line will ruin the diaphragm on the pressure switch. I hope you can find and fix the problem. If you need parts please send me your furnace’s product number. Please email us anytime if you have a question. Our email address is: firstname.lastname@example.org. If you think you have a bad pressure switch please click here to see the furnace pressure switches we sell. I hope you have a blessed day. Steve Arnold, https://arnoldservice.com
Below we have an Aprilaire Model 600 maintenance video made by HVAC.com. Many thanks to HVAC.com for making this informative video. Please click here if you would like to see the parts and supplies that we sell for the Aprilaire Model 600 humidifier. Please email us anytime if you have questions. Our email address is: email@example.com. We would love to help you out and have your business!
Below we have a YouTube video which explains how to replace a gas furnace gas valve. Please click here if you would like to see the furnace gas valves that we sell. Please email us anytime if you would like for us to look up a part for your furnace or answer a question. Our email address is: firstname.lastname@example.org. We would love to help you out and have your business!