I am installing a geothermal radiant floor heating system which includes the following components:

Florida Heat Pump 3T WW036 water-to-water heat pump which will use well water as its source. The terminals on the heat pump include C, O, Y, R

Honeywell TH5110D1006 Focus Pro non-programmable thermostat with terminals G, Y, C, W(O/B)

Grundfos UPS15-58FRC circulator pump, 1/25 HP, 115 v

Taco SR501 switching relay with terminals Rt, Wt, COM, N, H, 3, 4, 6, 5

Taco 5101G geothermal valve for controlling well water flow to compressor coil with terminals 1, 2, 3

The vague instructions with the heat pump suggest not using the heat pumps 24v source to control a valve.

The schematic with the geothermal valve are quite clear and show how to connect the thermostat, valve and heat pump so the valve opens before the compressor starts.

My questions include how to wire all components together correctly. Can a thermostat control more than one device? How does the thermostat control both the heat pump and relay or does the relay do all the controlling? Do I need a separate 24v transformer for the geothermal valve? I would then have 3 24v transformers (heat pump, relay and valve).

The system is so simiple and it's staring me in the face. I just want to be certain.

Thanks for the help.

What you need to do is engineer your system on paper. You have all the information from the parts and pieces you want to use. Trying to do this on a board such as this would be to time consuming and almost impossible to follow.

Lets face it. If you are going to be putting this together then you are the person that needs to figure it out since I am sure something will break someday and you are the person that needs the working knowledge of your system. Sorry but my time is limited and as you said the system is so simple.

Not knowing what the pieces are, your in possession of:

1. Heat pump transformer rating: This is nominally 40 VA or 40 Watts. Generally this is enough to control a reversing valve, a contactor and a thermostat. Many systems such as say zone controls or damper controls MUST use a separate transformer for this very reason.

2. What this likely means is that SR501 needs a separate power source for the contact closure that powers the valve sized for the valve. In high reliability installs such that's done with toxic gas detectors, the AC contacts are protected with ZNR's.

3. The SR501 is probably a special version of a Delay-on-make relay or relays giving contact closures for the pump, the valve and the heat pump.

These terminals or SR501: Rt, Wt, COM, N, H, 3, 4, 6, 5 suggest:

COM - low voltage common
Rt - Hot side of 24 VAC transformer (internal?) to R of thermostat
Wt - W of thermostat
N - Neutral primary of xformer
H - line or 120 V

3,4,5,6,

One pair are probably instant contacts an the other delayed.

ONE POSSIBLE SCENEREO

3 & 4 go to to where R and W go to turn on the heat pump
5 and 6 are series connected to a separate transformer and a valve.

I DON'T HAVE ENOUGH INFORMATION TO SOLVE THE PUZZLE.
IT'S JUST ONE POSSIBLE SCENEREO.

Rock and roll the transformer will carry, its all relay controlled and designed to work.