Monday, June 28, 2010

Heat Pump Repair Mysteries


HVAC technicians must go through a significant amount of training before they are certified by their state board to work on your air conditioner. However sometimes there are customers with problems with their HVAC systems that can only be figured out with step by step deductive reasoning... and sometimes a little luck. Modern AC units are less finicky than the old ones, but they also incorporate new technology that many Denver air conditioning services companies are not familiar with.

Heat pump technology in particular has advanced quite a lot recently. While the actual operation of a heat pump is simpler than an air conditioner, one in particular required a Denver HVAC technician friend of mine a long time unravel. The unit, a R-410A heat pump was installed and operating fine in the first year. Then summer began and the owner switched the unit over to cooling. It worked fine, but after a few days the owner noticed that the fan never turned off.

Now most experienced air conditioner techs would assume this was one of two things - a minor fault in the thermostat, or damaged compressor electronics. However, as the heat increased, the unit never turned off and the house did not cool down. So of course the owner calls her nearest Denver heating company.

This is the point where the tech must take all the evidence into account in order to investigate. Of course most AC techs do not view this job as a murder mystery, but the use of logical steps that need to be taken in order to figure out the problem are similar.

The first thing he notices is that it is hot. The interior is almost 90 degrees and the compressor is obviously not wicking any moisture out of the air. However at the compressor suction inlet, the temperature is 70 degrees, and 60 degrees at the outlet.

Our technician had to review the key facts: The unit worked fine in the summer. The blower fan did not shut off once switched to cooling. In many heat pumps there is a emergency back-up electric heating system. It is possible the heat pump never worked, because of moisture in the cooling lines or for whatever reason. During the winter, the unit may have used back up heating the whole time without the owner's knowledge. At this stage it is all speculation, because the problem could only be that the filter is clogged or that the compressor is dirty.

However it turns out that with 410A coolant systems, using older lines or synthetic oil cooling will clog the system. The technician used a systematic approach using the heat pump manual and his training. In the end our furnace repair hero had to drain the coolant and install new piping in the compressor.

1 comment:

  1. During winter, maintaining a warm home can be a great challenge especially if your furnace is broken.denver furnace repair

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