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| Joined: | Sun Nov 30th, 2008 |
| Location: | Bay Shore, New York USA |
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ELECTRIC HEATING TROUBLESHOOTING CHART[size=] Problem Possible cause Solution Furnace won't run 1. No power. 1. Check for blown fuses or tripped
circuit breakers at main entrance
panel, at separate entrance panel,
and on or in furnace; restore circuit. 2. Switch off. 2. Turn on separate power switch
on or near furnace. 3. Motor overload. 3. Wait 30 minutes; press reset
button. Repeat if necessary. Not enough heat 1. Thermostat set
too low. 1. Raise thermostat setting 5°. 2. Filter dirty. 2. Clean or replace filter. 3. Blower clogged. 3. Clean blower assembly. 4. Registers closed
or blocked. 4. Make sure all registers are open;
make sure they are not blocked
by rugs, drapes, or furniture. 5. System out of
balance. 5. Balance system. 6. Blower belt loose
or broken. 6. Adjust or replace belt. 7. Element faulty. 7.Replace element. Furnace turns
on and off
repeatedly 1. Filter dirty.
2. Motor and/or
blower needs 1. Clean or replace filter.
2. If motor and blower have oil
ports, lubricate. lubrication. 3. Blower clogged. 3. Clean blower assembly. Blower won't
stop running 1. Blower control
set wrong. 1. Reset thermostat from ON
to AUTO. 2. Relays faulty. 2.Replace relay. Furnace noisy 1. Access panels
loose. 1. Mount and fasten access
panels correctly. 2. Belts sticking, worn,
or damaged. 2. Spray squeaking belts with
fan belt dressing; replace worn
or damaged belts. 3. Blower belt too
loose or too tight. 3. Adjust belt. 4. Motor and/or blower
needs lubrication. 4. If motor and blower have oil
ports, lubricate. Problem: Electric heat will not come on or fan will not come on. 1. First and most important, Please make sure your electrical power is turned off before trying to repair or inspect any type of electrical appliance. I would recommend that you purchase a Multi Meter for some of the troubleshooting procedures listed. 2. Inspect the inside of the air handler or electric furnace for burnt wires. I find this to be a major problem. Electric furnaces use lots of electricity. Any connections that are the least bit loose inside the furnace will cause a heat build up, arcing and eventually a completely burned off connection. Before long the entire wire will be burnt off. Please see picture (compliments from one of our nice customers) below of a burnt heat sequencer. You can see where the heat build up and arcing has caused the terminals to completely burn off the left side! This looks like a three stack sequencer, because of the divisions in the layers of the sequencer:
3. Check your breakers or fuses inside the air handler. Again, make sure your power is off. A good multimeter would be nice to test your fuses. · Set the meter to the Rx1 scale (horseshoe), place one lead on each end of fuse. If the fuse is good, you should read zero. If the fuse is bad, you should read infinity (no reading at all). 4. If you still are not getting electric heat then you should test your sequencers to make sure they are working. You can make yourself a tester so you could get portable 24 volts without having the furnace power turned on by using a fan center connected to a junction box.
When 24 volts is applied across the two bottom connections (coil) on most sequencers, you should get continuity (a closed circuit) between the two terminals the one on the left M1 and the one on the right M2. You should also have continuity between M3 & M4. This might take 30 to 90 seconds after the 24 volts is applied before you get the continuity. If you do not get continuity then, the sequencer is no good.
What do we check if our electric heat is not working? There are a few basic things to check yourself. Other steps require an expert.
- Is the thermostat asking for heat? Be sure you know where all of the thermostats for your electric heat are located. Some heaters such as flush-in-floor electric heaters may use a wall-mounted thermostat while other electric baseboard heaters may have individual thermostats on each baseboard unit. In a bathroom with electric radiant heat in the floor, Is electrical power on to the heater? Check the fuses or circuit breakers that supply each electric heater. If the electric furnace does not seem to be making heat, the electrician or heating technician will use an ammeter to test each of the heating elements to see if one or more of them is not working. She will also check first to confirm that electrical power is on to the unit. If one or more of the staged electric heaters in the furnace has failed, the furnace may make warm air, but not enough warm air in very cold conditions. Check the air temperature rise across the electric furnace. When the furnace has been operating for 20 minutes or longer, typically the temperature at the return plenum (the lower thermometer in the sketch) will show about 70 deg .F. and the supply plenum temperature will be between 120 deg .f. and 125 deg .f. If the supply plenum temperature is too high (over130 deg .f.) something's wrong and you should call a heating service technician. Check radiant heat ceiling panels for wire interruptions. If someone drove an nail into a radiant panel or in the attic above they damaged a wire or heating panel, you may find that that room no longer has heat. We use a hand-held infra-red thermometer scanner to quickly check radiant heat floors and ceilings.
- Does the fan start up even with the fan lead removed from the thermostat ? A grounded heater coil can cause this to happen.
____________________
Retired US Army Refrigeration Specialist / NYC Board of Education HVAC/R (Retired)
40 Years HVAC/R service, sales,installations.