York Affinity Heat Pump

[jade97]

Greetings

I would like to better understand how my Electric Heat Pump operates on the control side. For instance, does the indoor/outdoor units have 'brains' in them or is all the control accomplished via the thermostat?

Twice over the last week, my HVAC failed to operate in the morning. The thermostat temperature was set to 66 deg F (lit up indicating the system was active), the house temp was at 62 deg F and the status shown on the thermostat had the inside unit status fan/heat 'off' and the outside unit status heat 'off'

After I reset the breakers twice (1st time the thermo said 'new hardware detected....would you like to continue & then the thermo locked up) and then the system started functioning properly.

Ever since this system was installed (new house 2015), I have been getting random error logs. These errors have ranged from "Fossil Fuel Mode Steering Error", "Communications to outdoor unit lost, check for loose or broken wires"

I've had three different HVAC Companies since new: 1. Builder Owned HVAC - Closed 2. Local one man outfit - Good, but Closed 3. Larger local HVAC - Current.

The 2nd guy stated his dislike for the thermostat installed on this system and that it could be giving false error codes. 3rd company, should be scheduling my winter maint. visit any day (unless they have since folded) and I will ask them to check the connections of the control wires.


The System is a York Affinity Heat Pump.

Outdoor Unit:
York YZH04812CA

Indoor Unit:
York MV20DN21CC
York 4HK16501506A (aux heat)
York FC62D3XC1A (evaporator coil?)

Thermostat:
York S1-TTSCC

If the wiring is tight and properly connected, could my thermostat be the issue? What would be a good replacement thermostat for this system, if needed?

 

[justinjoyal]

Your air handler is not compatible with your communicating thermostat and heat pump, so you probably have an interface module similar to this one :



Could it be faulty or improperly setup ?

 

[jade97]

Interesting, this is what the builder's HVAC guys included with the "upgraded" Heat Pump.

Where would that interface module be hiding?

 

[justinjoyal]

Interesting, this is what the builder's HVAC guys included with the "upgraded" Heat Pump.

Where would that interface module be hiding?

Probably somewhere around the air handler.

 

[jade97]

I don't see anything like this, unless it is installed inside the air handler....

The entire system was "spec'd" as a York Affinity System.

 

[fitter30]

This system is advanced. Don't think air handler matches the condensing unit to get the most out of the system. With all the numbers from air handler and condenser and thermostat would want to talk with a factory tech usually theres one at each branch. Doubt they would talk with a home owner need either a York dealer service person. From the install operation manual couldn't find the correct t stat number but did see info for using this condenser on a existing system.

 

[jade97]

The York S1-TTSCC02 shows compatibility with: CZE, CZF, CZH, YZB, YZE, YZF, YZH, YPLC, YP9C, TM9V, TM8V, MV, AHV

 

[Vicdog]

can you use emergency heat for now?

 

[jade97]

It functions normally 99% of the time. It just flakes occasionally, this time it flaked twice in a weeks time.

I'm just trying to understand the operation of the controls on this heat pump & figure out why this POS flakes out occasionally...... because I am an Engineer (or should I say have a BSEE, but haven't been an Engineer in 13 years).

Thank you for your responses?

 

[justinjoyal]

Well that

The York S1-TTSCC02 shows compatibility with: CZE, CZF, CZH, YZB, YZE, YZF, YZH, YPLC, YP9C, TM9V, TM8V, MV, AHV

Well that’s odd.

Your model number does not show communicating capability in the install manual. (MV20DN21C)

However, the other “C” added at the end of your specific model seems to be it. Usually, there is only one letter at the end of the model number. You got two Cs…

MVC20DN21C is a communicating air handler.

It’s like the C in the model number was misplaced or something, like they just added it at the end on the sticker as an option or whatever. It doesn’t even show on your unit’s warranty data. Anyways, in that case, you wouldn’t have the interface I refered to. It’s wired directly to your thermostat and heatpump.

There might be a problem with the thermostat ?

 

[jade97]

There might be a problem with the thermostat ?

That is what I was wondering....could also be a loose connection or wire broken within the insulation?

Also, that thermostat appears to be obsolete, so getting a compatible replacement might be challenging.

 

[RAB]

Could be how the wire was ran, is the cable shielded? Is the power coming in good all the time? Is the transformer tapped for the right incoming voltage?

 

[bonneyman]

Dang, that sounds like a thorny problem! I just hated when the manufacturers started coming out with all their new electronified systems, and it seemed like everybody and their brother introduced a programmable stat to save energy. Not all brands of stat would interface properly with every system - made for some sticky troubleshooting at times.
Then you have one that is spec'd as all compatible - and you still have issues. Dang.