running the heater (testing)

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1

Originally Posted By: mwest
This post was automatically imported from our archived forum.


Can a indoor split system gas heater be properly tested when then the temps


are over 80 degrees and will it damage the unit???


mike

2

Originally Posted By: jsavino
This post was automatically imported from our archived forum.


Forced warm air furnace or water system can be run up for test.


It will not damage the unit.

–
John Savino


HomeWorks Inspection Services, LLC


St. James, NY


631.379.4241

3

Originally Posted By: Brian A. Goodman
This post was automatically imported from our archived forum.


I worry about that too, particularly if the AC has been running. It seems to me the heat exchanger might not like the sharp transition from mid-50’s air to 120’s air, but I’m not a HVAC guru.


If I can I take the blower door off so the safety switch is open. Then I set the thermostat to heat, go back to the unit and press in the switch. If it fires off and runs okay for 10 - 15 seconds I let the switch go and reset everything. The heat works.

If there's something really dumb about that, please speak up, anybody.

4

Originally Posted By: kelliott
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Just being logical, it would seem to me that in a forced air furnace with the A/C coil sitting on top of the heat exchanger, with air moving up from the heat exchanger to the coil, the heat exchanger, being first in line in the air flow, isn’t going to experience much effect from the A/C coldness. The air flowing over it is coming from the house return, so the temp of that air is not going to be much different than on any cool winter day. So if anything was going to be in danger, my logic says it would be the a/c coil. And that’s not likely either, because the chilled freon in the coil is going to keep the metal from warming up too fast. Same principle as a car radiator in the dead of winter.


I’ve tested them same way, by setting therm. with blower door off, and just kicking the safety switch to watch it light off. If it lights up, burns long enough to kick the fan on, it’s OK. I do want to see the fan start and stop, in order to check the fan limit switch, so that requires the burners heat long enough to reach full temp, and then cool back down.


But don’t see any danger of damage to unit.


Keith Elliott

5

Originally Posted By: Brian A. Goodman
This post was automatically imported from our archived forum.


Just being logical, it would seem to me that in a forced air furnace with the A/C coil sitting on top of the heat exchanger, with air moving up from the heat exchanger to the coil, the heat exchanger, being first in line in the air flow, isn’t going to experience much effect from the A/C coldness. The air flowing over it is coming from the house return, so the temp of that air is not going to be much different than on any cool winter day.


Good point Keith.