High Pressure Lock out

[NDIrish147]

Have a couple questions about my heat pump. The hp is a ruud upql-030jez with a rgtm 070erbgs gas furnace. on saturday sometime while i was away from home the heat pump quit running. I am getting codes l23, and 28 out on the hp. I had the installing contractor come look at it today and he said the filter was dirty. the filter is a 3 month old 20x20x5 filter which according to him should last 12 months. would the filter cause this or is there something else going on?

[BaldLoonie]

23 is high pressure switch trip. Dirty filter certainly a cause since it causes low airflow and high pressure in heat mode. Any other cause of low airflow, such as improper blower speed setting, would do it as well. 3 months on a 5" filter is short but if the dust is very fine, that stops up airflow pretty quickly.

[heaterman]

I never tell a customer they will get so many months, weeks, days etc. out of a filter. Absolutely no way for me or anyone else to know that. All filtering systems operate under different conditions depending on a crap load of variables. Air flow is important, very important and he should have instructed you to inspect the filter at least monthly until you got a feel for how quickly it was going to load.

[NDIrish147]

I usually change it every 4 to 6 months no matter. I wasnt at the house when the contractor was there yesterday but he pulled out the old filter and left it out. what is the best way to tell when a filter needs changed?

[SBKold]

Airflow drop across filter can be measured.

[heaterman]

There are filter restriction indicators available that will tell you when it needs changed. Inexpensive and easy to install. Ask your contractor or do a quick Google search.