Mini split system heating, but not cooling well.

In May we had a Sanyo mini split installed in our guest house. It is a concealed duct (Model 26UHW72R) system.

When it was started up, it heated and cooled well. It has not been used much, but I noticed when I turned in on about a month ago, it wasn't cooling very well. After some investigation, I found out that while in cooling mode, the discharge temp from the vents is what ever the thermostat is set at. If you set the thermostat at 72, it puts out 72 degree air. If you set it at 64, it puts out 64 degree air.

On the other hand, when in heating mode, the discharge temps are around 100 degrees, and it works well.

I thought it may be a leak, but when the tech did the start up, it was triple evacuated, and pulled down to 50 microns. I figured with a leak, you would never be able to pull that kind of vacuum.

I have tried to get a hold of Sanyo tech support, but they don't seem to answer. The tech who did the install doesn't do many mini splits, so I may need to find someone in our area who is more familiar with them to help troubleshoot it.

It seems to me that it is some sort of control problem, but I'm not sure, I'm just a general contractor, so this isn't really my area.

Any suggestions would be great.

Thanks.

Hi Tirider and welcome to the forum.

What was the room temperature when you where taking those temp. readings?

While in cooling mode the room temp was between 75 and 80. With and outside temp of around 85 to 90.

In heating mode room temp of around 65 with and outside temp of around 45 to 55.

Thanks.

Hi Tirider,

I do not recognise the model but we in Europe sell similar system with differant model numbers to US.

Is the system a flexi multi or a mini VRF.

Any way with either the actual setpoint does not control supply air temperature.

If either is on cooling mode the supply air should be 12 C or lower on cooling and 38 degrees C on heating.

If you are not achieving 12 on cooling either the control sensor is being infulenced by fresh air or discharge air or as you say there may be a gas leak.

If you have not had any help from Sanyo USA re this by the time you recieve this mail please feel free to contact me directly and I will do my best to assist you.

Regards
T

pull down to 50microns, is it necessary?

Quote:

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Originally Posted by tirider

The tech who did the install doesn't do many mini splits, so I may need to find someone in our area who is more familiar with them to help troubleshoot it.

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The guy who triple evacuates to 50 microns has my vote. You won't find anyone more conscientious than him.

If he needs help, send him over here.

This may help:

http://www.sanyohvac.com/assets/docu...ries_Rev_2.pdf

in most inverter minisplits the set temperature DOES affect the outlet air temperature.... as the room temp approach the unit's capacity is reduced.. thus to increase runtime and efficiency...

most units including this sanyo have a chart where it changes frequency of compressor based partly on setpoint to room temp differential
-Christopher