Cool air from heat pump

Lootas1 · 03-04-2012, 04:33 PM

Just had installed a 3 unit Daikin ductless heat pump. Can't get much heat from the larger unit in the main part of the house. Richt now it is 50 degrees outside. I have that unit set at 86 degrees and it is only 69 in the main room. I notice the air coming from the vent is much cooler to touch than that from the other two units (which are maintaining room temps of 68 and 70 degrees). They are set at 68 for 24X16 foot master bedroom with cathedral ceiling and 70 for 12X25 foot room with 8 foot ceiling where control is also set for 70.
Seems to me something is wrong here but the installer has checked it several times and says everything is okay. Any pros out there who can explain this to me?

hvactech126 · 03-04-2012, 07:18 PM

I take it this is a multiple inside unit with 1 outside unit? If so, how does it run with the other units shut off?

Plumber101 · 03-04-2012, 07:35 PM

If I remember correctly each ductless unit has it's own TXV and one may be acting up or the could be a loose connection electrical.

Are you sure the the condenser for the ductless units can be set up for three units. I have seen units set up for two, three and four and have to check design of the condenser to make sure three units can be connected.

In the instructions there is also a preformance chart to help diagnose/

Lootas1 · 03-04-2012, 08:01 PM

HVA Tech, yah, one outside compressor hooked to three indoor whatever they are called. (as you can see, I'm no DIYer beyond changing a light bulb or something like that. Haven't tried running it with the other two units shut off. I'll try that in the morning when it will be cooler outside. (Now 50 degrees out there and holding at 70 in the house.
Plumber, See above comment about my knowledge of DIY. The installer has done a number of these and the literature he gave me says they have models for 2, 3 and 4 port. Don't know where to find my model number but it should be a 3MXSJVJU. The owner of the company has been out twice to look at it and he talked to the company that makes them and had me pushing buttons and telling him the number of beeps I was getting. Then he said it appeared that the electrician had switched a couple of wires. He went out and swapped them but it didn't seem to change anything. Don't know if he switched them back.

Plumber101 · 03-04-2012, 08:12 PM

Having the owner involved was going to be my next point of advice and I am glad to hear he is involved.

Still it sounds like a TXV is sticking or there is an electrical control issue. I have never had any big issue with a mini-split system but I have heard that some can be a real pain. Every manufacture has some sort of tech support which I understand the install is using. Just keep on them and I hope they can get it fixed for you.

Lootas1 · 03-04-2012, 09:11 PM

Thanks and I appreciate your John Wayne quote. Think life is tougher for me than for most but at 78, I'm just glad to be alive and know how to find help when I need it!

Plumber101 · 03-04-2012, 09:17 PM

For 78 I think you have a good handle on it. Just alot of variables to diagnosis over the net. Especially with three units off one condensers. And to boot every mini-slit maker makes then just a little different.

Lootas1 · 03-05-2012, 09:20 AM

Turned off the upstairs and lower floor units, which seem to be working properly. Left the main floor unit (the largest one) set at 86 degrees. This morning it is 47 outside and 65 in the house (only 21 degrees cooler than the thermostat is set for). Fan is set on high. Compressor ran for about 15 minutes pumping slightly warm air out of the unit and then shut down. Does this info help solve the problem?

hvactech126 · 03-05-2012, 11:42 AM

Yes. Call your installer back as it is not operating properly.

Patrick Eubanks · 03-05-2012, 11:07 PM

A Daikin is not your everyday mini-split. It is a variable refrigerant flow system. It allows a zone to cool while other may be heating. It could simply be a zone sensor setting problem or could indeed be a TXV. I would most definately call the original installer. This is definately not a DIY project, or a buddy thats in the business project either.