Mitsubishi FH Wall Unit I See Sensor Noises
Hi,
I have a newly installed a 5 zone hyperheat system (2 outdoor units). 3 of the 5 zones are served by FH wall units w/ the I see sensor. My 9k unit was making a constant dull spinning/revving/mechanical noise, until I disabled the I see sensor. The noise was constant, consistent, and sounded internal, it was not correlated with the actual movement of the external i see sensor (or to fan speed or other settings).
For those who have FH units- how much noise do they make compared to other wall units? Enough to be disruptive in a quite bedroom?
This claim is subjective (and the issue I’m having w/ my installer), but I’m certain that all three of my FH wall units make the sound at different intensities/volumes. Master Bedroom is the worst, Nursery is second worse, Downstairs is barely noticeable. My main concern is that my master bedroom unit was damaged prior to install and I want to get it corrected while the contractor is still in the picture.
Thanks,
Joe
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Replies
In a quiet bedroom it can be maddening because you will constantly hear it. Luckily I found in the hvactalk forum, you just use a pen or paper clip to press the sensor button on the remote till the sensor stops moving and you won’t hear the noise. For me it was 2 presses.
My guess is what you are hearing is the refrigeration liquid moving thru the unit.
Yes, it will sometime flow refrigerant thru this head when this head is not calling for heat. This is one of the down sides of multi splits. One of the other heads is calling for heat but its load is less than the minimum the speed of compressor so the system must dump the extra heat somewhere. So, the system heats this coil a little without running its fan.
Walta
When I commission I disable the isee sensor in almost all installations to avoid the noise issue you raise. As you point out there does seem to be some variation in the noise level of the servo motor from unit to unit.
Btw, if you don’t have the wireless mhk2 wall mount thermostats, I’d strongly consider adding those. The indoor units operate much more efficiently with them. I include them standard standard with all installations.