zwave sensor for hydronic system monitoring

[wingshigh.g]

Hi, I have a hydronic in floor heating system installed. The controller is currently the TACO SR506. I wanted to find a way to monitor when and for how long each of the zone works everyday.

I was thinking about a z-wave sensor that can report on/off of the relay from the TACO controller, but could not find one; or a z-wave sensor with contact temperature sensor that can sense the change in circulation water temperature, I could not find one either.

Can anyone provide me with some suggestions on how to achieve this? Thanks in advance.

[sparkman]

Is it 120VAC from the relay? If not, do you know what the voltage is? If 120V, you could use an Aeotec Smart Switch as it can sense 120VAC on one of it's switch inputs.

Cheers
Al

[randy]

Hi, I have a hydronic in floor heating system installed. The controller is currently the TACO SR506. I wanted to find a way to monitor when and for how long each of the zone works everyday.

I was thinking about a z-wave sensor that can report on/off of the relay from the TACO controller, but could not find one; or a z-wave sensor with contact temperature sensor that can sense the change in circulation water temperature, I could not find one either.

Can anyone provide me with some suggestions on how to achieve this? Thanks in advance.

That is a six zone controller and assuming it is wired in a conventional fashion, you have a 120V circulator pump for each zone. If that is the case three potential solutions come to mind

• A 120V relay across the supply to each circulator, with contacts controlling inputs on a digital I/O device - Arduino or HomeSeer
• If you are using Z-Wave thermostats monitor the operating state child device - making sure the device is reporting or polled frequently.
• A OneWire device on the supply side to each zone to monitor temperature rise when active. Use an Arduino or EDS OWServer to interface the OneWire devices with HomeSeer.

In my system I use essentially a combination of all three. I use the Arduino for digital I/O and OneWire temperature sensors with EDS OWServers. A thread describing my system is linked in my signature below. It has expanded since that initial thread, but the idea is the same. I monitor supply and return temperatures, the thermostat's operating state and the zone valve end switches. Assuming your system is as I described above, you don't have zone valves. That degree of information gives me graphing of zone run times and temperatures, can warn me of a failed zone valve, valve end switch or if the boiler fails to run.

[wingshigh.g]

Wow, this is great! Thank you gentlemen.

I am not a heating/cooling guy sot I guess it is even worse when I take something for granted. I had thought the relay for that system was 24V therefore the motors are powered by 24V supply from the TACO controller?

If it is 120v then I think a inline AeonTech sensor should at least be able to tell me when it is working, correct? The OneWire solution is definitely interesting. Will investigate.

Thanks again!

Forgot to confirm, Rprade, you are right, my controller is without the zone valves, to me, it seems that the zone valve system would require less number of pumps and therefore more efficient?

[randy]

Wow, this is great! Thank you gentlemen.

I am not a heating/cooling guy sot I guess it is even worse when I take something for granted. I had thought the relay for that system was 24V therefore the motors are powered by 24V supply from the TACO controller?

If it is 120v then I think a inline AeonTech sensor should at least be able to tell me when it is working, correct? The OneWire solution is definitely interesting. Will investigate.

Thanks again!
H
Forgot to confirm, Rprade, you are right, my controller is without the zone valves, to me, it seems that the zone valve system would require less number of pumps and therefore more efficient?

If it is wired conventionally it is 120V. I attached the manual below.

The pump motors are usually 1/32-1/16P so the power they consume is minimal, but would be more than a zone valve. Looking at a Taco 1/25HP pump the spec sheet shows .71A at 115V. That would be around 85-watts. I think the sheet is stating maximum current flow, not operating. The operating current on mine is about 45 watts. The new variable speed circulating pumps draw between 9-42 watts. Either way, it is a nominal amount of current. A rule of thumb is that a full-time watt is about $1 per year at $0.11/KWH. That is in the US, I don't know what the rates are on your side of the border. Since these pumps see intermittent as well as seasonal usage, they are probably running less than 5% of the time on an annualized basis.

Multiple circulator pumps is the more common design currently as it tends to give each zone a predictable and constant flow rate. That is much more important in a floor installed radiant heat system. My system uses wall mounted heat exchangers which are more forgiving of flow rate changes.

The AeonLabs SE switch would tell you the current that the pump is consuming and you could graph the consumption, or trigger a virtual device when it is running.

[wingshigh.g]

Thank you very much. That is very helpful.

I have verified my pump, it is Bell & Gossett Circulator, model WRF-22, 92Watt.

I am ordering the Aeon Labs micro switch.

My current thermostat is the two wire type, converting the z-wave means I have to re-run the wire. That seems to be a task for me. That is why I have not converted them to z-wave thermostat yet. I don't want to use the CT100 based on some of the information I read. Any suggestion on that?

Thank you again.

[randy]

Thank you very much. That is very helpful.

I have verified my pump, it is Bell & Gossett Circulator, model WRF-22, 92Watt.

I am ordering the Aeon Labs micro switch.

My current thermostat is the two wire type, converting the z-wave means I have to re-run the wire. That seems to be a task for me. That is why I have not converted them to z-wave thermostat yet. I don't want to use the CT100 based on some of the information I read. Any suggestion on that?

Thank you again.

I hesitate to recommend the CT100, since it is much maligned around here. That said I have 8 of them and they have been perfect. They have one flaw, two of the child nodes have to be polled as they do not provide instant status - Fan State and Operating State. I run events that change the settings on all 8 of them several times a day and they never fail. The clocks are automatically set when included and they are easy to read and adjust. The temperature is accurate on them to within a degree or so and they can be calibrated. They also are fairly consistent on humidity, but I believe they are only accurate within +-10%. Most importantly, my wife likes them

[wingshigh.g]

Thank you. May I ask why you hesitate to recommend the CT100? I just wanted to see some real life opinions here.

[randy]

Thank you. May I ask why you hesitate to recommend the CT100? I just wanted to see some real life opinions here.

Based on my experience I would highly recommend it. My concern is about the large number of people who have reported problems with the thermostats. I know they do not play well with HS2, but a fair number of people have reported trouble with HS3. They have worked fine for me since I installed them early this year, but there were some errors with the earlier Z-Wave plug-ins. I am suspicious that some people are trying to use them on batteries or not being careful including them in the network. Look at this thread and specifically post 14 where I describe how I included mine.

[wingshigh.g]

Rprade, I just realized that there is a flaw in my design. The aeon tech switch needs to have the 110v input at all time to be able to operate. However if my current two wire mercury thermostat does not close, the relay in the TACO controller won't close, therefore there will be no 110v power to the pump, and therefore no power to the aeon tech switch.

So it looks like I just need to give up the TACO controller and use only the zwave solution.

Please let me know if I missed anything.

Thanks.

[sparkman]

When I recommended the Aeotec, I envisioned it being powered by a continuous 120VAC source and then the hot output of the relay would tie into one of the switch/sense terminals of it. Something like this:



It would strictly be used to update HS using z-wave that it was on and can be used in parallel with other requirements.

Cheers
Al