Circulator Operation with ODR

dgoldstein

This is my second season after having upgraded my Munchin 80M R2 with the Vision 1 ODR for my HWBB heat system. The circs for my three zones are Tacos (007 and a 009). Each zone has it's own T-stat.

The zones are:

• utility room (never gets turned on and all circuit feed valves are closed since the hot water heater and boiler live in this room, so it never gets anywhere near cold - kinda a waste of copper and a circ IMHO)
  
• 2nd-floor (seldom ever run this circuit since the heat from the 1st floor usually keeps this room at 60*+ during the winter and we don't inhabit up there too often)
  
• 1st floor primary living space (kitchen, living room, 3 bedrooms, 2 baths, & laundry room).
  

I have the 1st floor living space T-stat set to 80*F, indoor temps so far have been relatively steady at 71-73*F with outdoor temps in the 42*-74*F range.

My t-stats and circulators are wired into a Argo zone relay control module. The Argo ties into the Munchkin.

Is it considered normal operation when T-stat is calling for heat, even if the boiler is in Warm Weather Shut Down (68*F), the circulator should still run?

hot_rod

dgoldstein said:

This is my second season after having upgraded my Munchin 80M R2 with the Vision 1 ODR for my HWBB heat system. The circs for my three zones are Tacos (007 and a 009). Each zone has it's own T-stat.

The zones are:

• utility room (never gets turned on and all circuit feed valves are closed since the hot water heater and boiler live in this room, so it never gets anywhere near cold - kinda a waste of copper and a circ IMHO)
  
• 2nd-floor (seldom ever run this circuit since the heat from the 1st floor usually keeps this room at 60*+ during the winter and we don't inhabit up there too often)
  
• 1st floor primary living space (kitchen, living room, 3 bedrooms, 2 baths, & laundry room).
  

I have the 1st floor living space T-stat set to 80*F, indoor temps so far have been relatively steady at 71-73*F with outdoor temps in the 42*-74*F range.

My t-stats and circulators are wired into a Argo zone relay control module. The Argo ties into the Munchkin.

Is it considered normal operation when T-stat is calling for heat, even if the boiler is in Warm Weather Shut Down (68*F), the circulator should still run?

Why is there a call for heat if it is that warm outside?

The pumps could b e tied to the ODR also, so they would run only when there is a boiler call.

dgoldstein

The t-stat(s), when set to "Heat On" and the temp set to 80* - effectively making them a On/Off switch, will activate the Argo's relay for that zone's circulators regardless of whether or not the boiler in in WWSD.

The boiler's computer doesn't seem to have any control over the circulators the way it's currently wired.

I suppose I might need to put in a call to HTP.

hot_rod

Often times the "dry" contacts in the Argo call on the boiler.

So a thermostat call for heat turns on the pump and boiler at the same time.

Even if the boiler is always powered to keep the control on, there should be a call for heat terminal or wires to run to the Argo?ler c

dgoldstein

Bob,

I took a closer look at my system wiring last night and also tweaked my ODR curve and WWSD after calling both Argos and HTP about this.

Again, my Munchie is only used for space heating and has no interaction with my DHW system (That's a Rheem PowerVent 50gal gas).

The boiler has three groups of external wiring:

• 120VAC Input: White(Neutral), Black(Hot), Green(Ground) - supplied from main house breaker panel
  
• 2 Normally Open T-stat gray wires - connected to the Argos AR861-3II terminals A & R
  
• 120VAC/4-amp MAX Output: Brown(Neutral), Orange(Hot), Green(Ground) - for primary circulator (Taco 007-F5)
  

The way my system currently operates:
1. When one of my zones/t-stats calls for heat the corresponding zone LED is illuminated in the Argos - with my t-stat for my 1st floor zone set to 80*, it's always calling for heat even if the interior temp is comfortable, powering the zone's circulator continuously.
2. The Argos relay for the corresponding zone will then close.
3. A/R terminals will close starting the boiler via the two gray boiler t-stat wires, the primary circulator turns on (Taco 007-F5).
4. The corresponding GZ/HZ (zone circulator) terminals will be energized with 120 Volts.
5. My boiler will go into WWSD when the outdoor temp is 70*+F.
6. My Max Outdoor Design temp is 70*F, Min Supply Water Temp is 95*F.
7. My Min Outdoor Design temp is 13*F (as per my area from ASHRAE(sp?) Manual J), Max Supply Water Temp is 150*F.

I believe I need to adjust my t-stat(s) to be the same temp as my WWSD. This will shut down the circulators once my comfortable indoor temp (70*F) is hit.

Though, I suppose by not continuously circulating the water there may be efficiency losses or maybe not since the water in the HWBB is going to continue to emit heat from the water until it falls below the effective emitting output temp (~90*F).

Ultimately, I just want to make sure that the circs aren't running unnecessarily.

thoughts?

hot_rod

Exactly!
If the boiler is piped primary secondary and has it's own circ pump, make sure it shuts down on heat call also. If not they can ghost flow some heat energy into the BB loops without adequate check valve protection.

If the system is sized properly, and reset adjusted, on a design day you should see constant or near constant circulation, and constant boiler run. With enough fiddling you can make this happen. Kurt SWEI had a good post somewhere about his procedure for fine tuning ODR controls.

Why is your one t-stat set at 80f? You should be able to set it where you want the room temperature to end up. Turning it up will of course keep thing running and flowing. Constant circulation will cost you pumping energy, on a low mass baseboard system, not sure it is necessary for comfort?

dgoldstein

How do I know if my boiler is piped primary secondary?

I presume a "design day" would be the Man J suggested temp? In my area 13*F. If so, I'll probably see that temp some time between December and March.

I still need to measure all of the emitter lengths and figure out if the system is actually properly sized. I'll get there eventually. For the time being, I've had to "micro-zone" our bedroom to be cooler at night by closing the vents on the HWBB housings.

I've interacted with SWEI on some of my other ODR related posts. I don't recall if it was him or someone else recommend that I set the t-stat temp up way high to essentially keep the system on all the time and let the ODR control the boiler fire rate and then adjust the curve until I get the desired indoor temps.

I've moreorless done that and am making small tweaks, but I suppose now the t-stat setting can come down to my preferred indoor temp since I guess leaving it ON all the time was just an aid to dial in the ODR curve - or so it seems now that I think about it.

The primary circulator coming out of the boiler doesn't have a internal check valve. I'm not sure if one is installed anywhere in the system. All of the Taco circs are non-IFC versions.

Gordy

The thermostat is a high limit switch as setup. But why set to 80? The theory with the method is other sources of heat warming a zone. Fireplace, sun, occupants etc. so thermostat is high limit. So no call for heat.

If the odr curve is set correctly then it should function off the outdoor sensor. Not the thermostat. Dialing in the curve is the tedious part.

dgoldstein

Gordy,

Like I said, someone else on here suggested I set the t-stat to 80 to keep the system running so I could dial in the ODR to achieve my desired indoor air temp. I don't think I was supposed to leave it at 80* indefinitely after the ODR cure was close to perfect.

I think I'm supposed to now set it to my desired indoor temp or just a few degrees above it. Right?

Gordy

Correct. Sorry I did not understand that is what you are doing right now is dialing in the reset curve. I thought that had already been done.

dgoldstein

Gordy,

I'm still tweaking the curve a bit, but as you can probably tell, am trying to more fully understand how the each of the components in the system should function given the ODR control.

I'm just wasn't sure what function the t-stats performed if the ODR and curve are essentially telling the boiler how hard to run and when.

And, understanding when the primary and zone circs shouldn't be running.

I appreciate your insight!

Gordy

Primary should come on with boiler operation along with any zone calling for heat.

In a perfect world with a mod/con boiler sized to the load to its highest output for all zones calling and to its lowest output with one zone calling would near run 24/7.

The thermostat would just function as a high limit in case other sources of heat effect room temp. Otherwise the ODR makes the call based on outdoor temp, and supply temp sensor, so in order for it to function properly the sensor needs to know water temp so constant circulation works best.

hot_rod

It depends a bit on how the system is piped. With that boiler you should have some sort of primary secondary. With P/S some times you have a dedicated boiler pump, a primary loop pump, then your zone pumps off the primary loop, shown below. So constant circ becomes a bit more complicated. Running 5- 80W pumps constantly might not be ideal.

dgoldstein

There is a Taco 007-F5 installed on the Return/Cold side of the boiler.

The 3 other circs (mix of 009 & 007) are each on the cold return side of their respective zone loops.

I just installed Taco's HSS and am going to try my hand at drawing up my system, and/or taking some pictures for reference.