Heat pump question

paulmars

I just replaced 3 ton r22 ac & oil furnace with 2 ton r410 heat pump & matching AHU.

I know they don't produce equally hot air, but is this normal:

45-50F outside between midnight & 5am. Thermostat set to 70F. Cycles on for 15-17 minutes, then off for 2.5 to 3.5 minutes. Repeat. Repeat. Repeat. Next night ditto

1952 cmu house with 9 tight sealing but non insulating plain glass windows & well insulated attic & 2 metal entrance doors. Central west florida. Central air was added by previous owner. I had it replaced in 2002 w\above mentioned 3 ton. Then again a week ago w\heat pump.

800 sq ft house. Yes I now know they installed too large cooling system 22 years ago. It also had 18x12" 8 merv filter (yes I now know 18x12 is way too small)

New unit just installed came with 16x20 fiberglass filter.

Old heater had considerably more off time & less on time.  Maybe about 5 on & 10-20 off. Old cooling was the same. Telling me that house is insulated good

I can feel much more air coming from the vents now then the old 3 ton system w\small return. I just looked & old blower fan blades very dirty. I think i remember changing years ago to pleated because sometimes the fiberglass would pull in, resulting in unfiltered air.

Is 16 minutes on, 3 off normal?

Btw burner, oil tank, smoke tester, manometer & other oil furnace equipment for sale. Ill direct you to the online ad if u ask.

Btw can i use a more restrictive merv 5 or 8 16x20 filter? This air handler is speced at 700 cfm.

Thanks,
Paul
.

Ironman

What’s the CPH set for on the thermostat?

ratio

Maybe a refrigerant pressure switch cycling things?

Hot_water_fan

Switching from a big oil furnace to a 2 ton heat pump will always result in longer run time. It’s smaller!

bburd

What make and model heat pump do you have? Some of the newer units modulate and will have longer run times at reduced capacity. Others are either on or off and their run time will be almost directly related to the heating load.

bjohnhy

Is the thermostat calling for heat the entire time?

Or is the thermostat calling for heat for 16 minutes, demand met, thermostat off, then 3 minutes later, calls for heat again? If this is the case, thermostat may be located too close to air vent. You noticed more air being pushed through vents, is this increased air flow now landing right on to thermostat?

16 min on, 3 off, is not normal.

paulmars

thermostat is where it has been since before 1986. No this one is not that old. Its in hall which has no vent. yes thermostat is turning it of and on. How else would it maintain set temperature?

WBHL244AB

W4H5S24AKAAAABAA (yea five followed by S and yea four As in a row)

paulmars

oh yea

heat pump osculating noise sound can be played here. u wont need to dnld it.

bjohnhy

https://forum.heatinghelp.com/discussion/comment/1833623#Comment_1833623

If this is the case, it is possible the "swing value" on the thermostat is too narrow or tight for the new system.

Can you post the thermostat model?

I am sure you know all this but for the masses: Some thermostats have and adjustable swing value. Some thermostats have settings to adjust the cycles per hour, Minimum off time, and minimum run time. But setting to a wider swing value will increase all of those variables.

A common value is +/- 0.5 degrees or a full 1.0 degree of swing. I cannot imagine that house cools off a full 1 degree F in just a 3 minute time span to then call for heat again. I'm betting its a problem with the thermostat and not the heat pump.

I am assuming the house feels comfortable.

There have also been cases where there is a cold draft (usually unsealed wiring penetrations) into the wallspace immediately behind the thermostat, that can produce those frequent on/off symptoms. This is found by turning on multiple house exhaust fans, taking thermostat off wall, and check for a draft coming from the wiring penetration. Even more rare, there is a duct leak into that wall space, this would usually feel like the house is not coming up to setpoint.

I have seen at least one thermostat "fail" in that the effective swing tightened up on its own after 15 years of use.

Re the audio file, I think heatinghelp marked it as unsafe. I am not able to listen to it.

paulmars

Honeywell pro th4110b

Looking at page 4 & 5 I dont know if all those wires are correct. See my pics.
He told me he installed that w-y jumper.
He told me he set that switch on page 6 to heat pump.
Page 8:
Setup function 1 was set to zero. I chng to one.
No setup function 5, it skips to 9.
Mistakenly I may have chnged setup functions 9, 13, & 15.
I reset them to:
Setup function 9 to three.
Setup function 13 to zero.
Setup function 15 to five.

paulmars

heat pump osculating noise sound can be played here. u wont need to dnld it.  https://files.fm/u/sj7vpp4b33?share_email_id=159aebb&share_show_reg_form=true#/view/kydyzdn9wy

House temp stays constant, so in that regard thermostat is working

JMWHVAC

I take it your question is, " Is it normal for my unit to have to run 84% of the time to maintain room temp at an outdoor temp of 45-50?" What is the air temp going into the Air handler and what temp air is comimg out of it after 15 minutes of running?

bjohnhy

https://forum.heatinghelp.com/discussion/comment/1833770#Comment_1833770

Let us know if that helps. I wouldn't hesitate to try 2 for the compressor cycles per hour.

Also, I don't see any pics posted by you. But the audio file is now available to listen to.