# heat pump cycling before reaching set point **URL:** \ **Category:** Inspecting HVAC Systems\ **Created:** [December 8, 2012, 1:28pm UTC](https://forum.nachi.org/t/heat-pump-cycling-before-reaching-set-point/73941 "2012-12-08T13:28:39Z")\ **Posts on this page:** 6\ **Page:** 1
**Author:** ![gheller](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/gheller/32/1120_2.png) [@gheller](https://forum.nachi.org/u/gheller)\ **Post date:** [December 8, 2012, 1:28pm UTC](https://forum.nachi.org/t/heat-pump-cycling-before-reaching-set-point/73941/1 "2012-12-08T13:28:39Z")
Our new house has a Goodman 4 ton hp. We leave the unit off at night and house temp gets down to around 65 degrees and the outside temp is about 30 degrees. When we wake up I turn the unit on with a 70 degree set point. The unit will cycle several times prior to reaching an inside temp of 70 degrees. I’ve told the builder that this unit needs to be “trimmed”. He disagrees. Should I be worried about “slugging” the compressor? ---
**Author:** ![cbottger](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/cbottger/32/206_2.png) [@cbottger](https://forum.nachi.org/u/cbottger)\ **Post date:** [December 8, 2012, 1:45pm UTC](https://forum.nachi.org/t/heat-pump-cycling-before-reaching-set-point/73941/2 "2012-12-08T13:45:53Z")
> [@gheller](#): > > Our new house has a Goodman 4 ton hp. We leave the unit off at night and house temp gets down to around 65 degrees and the outside temp is about 30 degrees. When we wake up I turn the unit on with a 70 degree set point. The unit will cycle several times prior to reaching an inside temp of 70 degrees. I’ve told the builder that this unit needs to be “trimmed”. He disagrees. Should I be worried about “slugging” the compressor? Not to worry about slugging the compressor, they are designed to operate in cold weather. What do you mean cycle several times meaning into defrost or cycling off period before set point ---
**Author:** ![gheller](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/gheller/32/1120_2.png) [@gheller](https://forum.nachi.org/u/gheller)\ **Post date:** [December 8, 2012, 1:56pm UTC](https://forum.nachi.org/t/heat-pump-cycling-before-reaching-set-point/73941/3 "2012-12-08T13:56:43Z")
It will run about 10 minutes and cycle off. Then it comes back on for 10 or 15 minutes and cycles off again. At a 30 degree outside air temp I don’t think it should go into a defrost mode that quickly. ---
**Author:** ![cbottger](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/cbottger/32/206_2.png) [@cbottger](https://forum.nachi.org/u/cbottger)\ **Post date:** [December 8, 2012, 2:51pm UTC](https://forum.nachi.org/t/heat-pump-cycling-before-reaching-set-point/73941/4 "2012-12-08T14:51:46Z")
> [@gheller](#): > > It will run about 10 minutes and cycle off. Then it comes back on for 10 or 15 minutes and cycles off again. At a 30 degree outside air temp I don’t think it should go into a defrost mode that quickly. You have a problem Call a tech and send the builder the bill, or at least call the installing contractor and bypass the builder most contractors in my area place a sticker on the unit with their phome # the unit should still have a warranty. ---
**Author:** ![dandersen](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/dandersen/32/59398_2.png) [@dandersen](https://forum.nachi.org/u/dandersen)\ **Post date:** [December 8, 2012, 3:08pm UTC](https://forum.nachi.org/t/heat-pump-cycling-before-reaching-set-point/73941/5 "2012-12-08T15:08:49Z")
If the thermostat shuts down when the air temp at the thermostat has not reached set point; it is possibly the “anticipator” in the thermostat is not set right. If the temperature reaches set point but falls quickly after shut down; the wall the thermostat may not be insulated and there is a bypass to the exterior. [![](http://i572.photobucket.com/albums/ss162/dandersen_02/IR_0198C.jpg) ](http://i572.photobucket.com/albums/ss162/dandersen_02/IR_0198C.jpg) [![](http://i572.photobucket.com/albums/ss162/dandersen_02/1076.jpg) ](http://i572.photobucket.com/albums/ss162/dandersen_02/1076.jpg) Air stratification can occur and it is 100F at the ceiling and 40 at the floor. This will cause a short cycle. [![](http://i572.photobucket.com/albums/ss162/dandersen_02/MIA-horz.jpg) ](http://i572.photobucket.com/albums/ss162/dandersen_02/MIA-horz.jpg) ---
**Author:** ![mgratton](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/mgratton/32/58251_2.png) [@mgratton](https://forum.nachi.org/u/mgratton)\ **Post date:** [December 8, 2012, 7:01pm UTC](https://forum.nachi.org/t/heat-pump-cycling-before-reaching-set-point/73941/6 "2012-12-08T19:01:46Z")
> [@gheller](#): > > It will run about 10 minutes and cycle off. Then it comes back on for 10 or 15 minutes and cycles off again. At a 30 degree outside air temp I don’t think it should go into a defrost mode that quickly. Thermostats installed too close to register will cause that problem. I relocated mine away from the 50in. plasma.