Wiring Logamatic R2107 to Single Zone Pump Control

jrutig

Equipment: Buderus boiler with Logamatic R 2107. Single grundfos circulator for the heating connected to 5 zone valved hydro air handlers. Single grundfos circulator for the DHW. 

Problem: heating circuit pump dead heading when thermostats not calling for heat. (Logamatic constant circulation unless DHW priority, WWSD or condensation protection)

I finally convinced my hvac company incorrect equipment set up was responsible for dead heading the circulator pump. A Grundfos single zone pump control was added. We were able to identify wiring running from each zone valve end switch back to the boiler room for the pump control.  My question is was it wired correctly?

Based on what I understood this was how it should be wired:

However this is how they actually wired it:

Nothing I can see connects the Logamatic 63 terminal to the pump control switch. Am I wrong or does this eliminate DHW priority and WWSD?  Anything else I should be concerned about? 

HVACNUT

Terminal 63 is a constant 120v output, unless as you stated DHW priority or WWSD. The diagram is correct. 

Can't really tell how its wired from the pics but if it doesn't follow that diagram, its wrong. As long as the DHW is wired into the 2107.

jrutig

The DHW circulator is wired to PS 24 and 25. Nothing wired to PH 61or 63 (previously the heat circulator wired here). 

Now the heating circulator is wired to the single zone pump control. The zone valve end wires to TT on the pump control turn the heating circulator on and off. 

Is there anything I might be missing here. I asked my hvac guy specifically if this was wired correctly and showed him the Buderus diagram above. He claims his work is correct and DHW gets priority. I don’t see how but at this point I’m dangerously close to calling out this fellow (who owns the company)  as incompetent. I’d very much prefer to be the one who is wrong here. 

HVACNUT

The indirect will still bypass ODR and run to high limit, but it won't be priority. 
The 2107 is not an aquastat. It doesn't care if there's any heat zones at all. It just wants to find the perfect boiler temperature compared to the outdoor temperature. Terminal 63 is for constant circulation, and the 2107 would adjust its temperature accordingly. But in the U.S. we don't use constant circulation often so we needed a "get around".
The relay should be wired as shown, with H constant 120v, and 3 to 63 on the Logamatic. 4 N.O. to the circulator.
The way it is, you also lose freeze protection and circulator exercising. 

I wouldn't call the tech incompetent, just not familiar. And maybe a little stubborn. 

pedmec

system circulator should not come on until end switch on zone valve is closed, which would mean valve is open and you can get flow. i don't see any controls for the zone valves. this set-up is not complete

pedmec

this is how it should be wired using zone valves. 63 is constant power so you will have it go thru the normally open contact at a multizone switching relay. when a zone valve closes the end switch will close the switching replay to turn circulator on.

jrutig

The zone valves are all wired to low voltage transformers directly at the air handlers. They are opened whenever the air handler thermostat calls for heat.  The end wires from all the zone valves are run back to the boiler room and are connected to TT on the single zone pump control.

So for example: thermostat calls for heat to AH, zone valve at AH opens using its own power source, then zone valve end wire communicates to pump control to turn on pump. 

Does that help?

TAG

What's the point of the R2017 in this application? I was always told in was designed for constant circulation .. be it set up for radiant or radiators (typically panel in Germany). Since it's doing ODR ... how will this work with hydro-air that needs high temp water to heat the air on and off?

Can you have hydro always running with low air output and the system set on constant circulation to the main unit?

Seems the 2017 needs to be switched out to a simple control that brings it up to full output temp --- that the hydro-coils need

jrutig

Thats a good question. My understanding is the R2107 still has benefits even in a hydro air setup. I had to contact Buderus to find out there is a specific hydro air program the installer should have selected (which they hadn’t done). Also I believe the R2107 still does things like DHW priority, WWSD, Condensation protection, and pump exercising, etc on top of modulating the heating curve based on ODR. Had no issues with getting and maintaining room temps over the winter. Only problem was when there’s no call for heat and the zones are closed, the constant circulation was dead heading the pump. I worked around this by opening one of the shut off valves so there was always at least one circuit for water to return. 

The whole and only point of the single zone pump control was to stop the dead heading. And my understanding is if you wire it correctly (i.e. Buderus schematic) you can easily achieve this without losing other R2107 benefits. 

HVACNUT

@jrutig, just have it wired like the diagram you posted. That is correct for your application. There also are settings for the type of emmiters you have in the programming. I believe the number is 7 but would have to check the manual to see which section.

BDR529

2107 is useless in hydroair application. You need the temp rise.

End up pulling your hair out with that control. Honeywell Control and be done with it.

jrutig

So the problem is I asked for an explanation why the wiring was different from the Buderus diagram and they guy became irate. Previously he claimed  his wiring provided DHW priority. Then he admitted it didn’t and said his job was to stop a pump dead heading not to wire it as the schematic showed. Frankly his behavior left me beyond puzzled. 

It’s pretty clear to me now the guy is a hack, and an **** as well. Im just going to rewire it myself.