Advice on McQuay R-410A MHC Standard Range & MHW Geothermal

[gonzonia]

Thank you! You're doing more for me than McQuay is. You do hear something. I never paid attention to a "whoosh" per se, but you can definitely tell when it switches over to heat.

I've got the thermostat manual I haven't found anything that will help. I think the problem is at the receiver end. The thermostat does not have an "auto" it is either HEAT, COOL, or OFF. It's set to HEAT and I've set it to HOLD the temperature. Since it's a wireless thermostat, half the booklet is about installing nodes.

If it helps, the booklet I have has the following info:
Operation & Maintenance Manual OM 897-1
Group: PDAC/PDHP
Part Number: 668111002
Date: August 2009

The Heat Pump booklet info
Installation & Maintenance Data IM 985-2
Group: WSHP
Part Number: 669479302
Date: November 2011

[motoguy128]

SOUNDS LIKE it is coming on in cool mode and when the stat drops a bit, it brings on electric heat instead and you finally get heat. When it is heating, do you hear the compressor running? Do you hear a woosh as the reversing valve switches to heat?

I'll research a bit more later. Trying to find setup manual for that wireless thermostat.

Didn't think of that. I didn't think these units had supplemental heat. That would make sense. SO the valve is wired backwards or the wireless thermostat module on the unit is wired backwards.

I'm a little disspointed at ht poor level of supprot your getting form this service company. I thsi is what it's doing, it should be obvious ot any tech that it's going ot bakc up heat just from hearing that the compressor is still running, but heat starts comming out without hte reversing valve switching. You cna also use one of them crazy devices... a multimeter and do some real troubleshooting.

[BaldLoonie]

The McQuay lit says they can have backup. Being a residence, wouldn't be surprised if it did. But can't say for sure.

Before it starts to heat, the compressor is on for cooling and it is putting old cold air. Do you hear the compressor stop or does it suddenly start heating? Listen for the woosh if the reversing valve is changing from cool to heat.

Beyond that, gonna take someone there who knows the controls to figure it out. Probably isn't major, but a programming issue.

[gonzonia]

When it switches from cold to heat the compressor definitely stops.

The compressor goes off. The fan stays on for a minute or so and then you hear the heat kick in.

[BaldLoonie]

When the heat kicks in, do you hear the compressor resume?

[gonzonia]

When the heat kicks in, do you hear the compressor resume?

I would say yes. It sounds like the compressor is coming back on.

[gonzonia]

Talk to more people at McQuay now. They are going to come next week and hook up a wired thermostat to see if it does the same thing.

[gonzonia]

I'm happy to report that I have another update. Thought it's not a favorable one for McQuay or the installer.

I was having dinner with a friend tonight who works in the home automation industry. I described the problem to him and his response (after telling him only once), "Sounds like some wires are wrong." Since he's dealt with many wiring issues including connecting thermostats with home automation systems, he offered to come take a look. After looking at the manual for the remote control node and how it was connected, he found the problem. He did in 20 minutes what a McQuay trained tech could not do in 2 separate visits.

It turns out that whoever installed the nodes (I don't know if that was the installer or the factory), they were wired in the PTAC & Heat Pump Configuration not the Water Source Heat Pump configuration. Switching to the correct configuration fixed the problem.

[BaldLoonie]

Glad it's fixed but sure makes the installer look like a maroon.

[motoguy128]

A bad example of a tech relying on exerience only, making bad assumptions that the wiring wss correct and not tsking a minute to read the manual.

Sorry to hear you had this issue. It unfortunately makes the industry look bad imo.


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[beenthere]

I'm happy to report that I have another update. Thought it's not a favorable one for McQuay or the installer.

I was having dinner with a friend tonight who works in the home automation industry. I described the problem to him and his response (after telling him only once), "Sounds like some wires are wrong." Since he's dealt with many wiring issues including connecting thermostats with home automation systems, he offered to come take a look. After looking at the manual for the remote control node and how it was connected, he found the problem. He did in 20 minutes what a McQuay trained tech could not do in 2 separate visits.

It turns out that whoever installed the nodes (I don't know if that was the installer or the factory), they were wired in the PTAC & Heat Pump Configuration not the Water Source Heat Pump configuration. Switching to the correct configuration fixed the problem.

Post #7.