Which thermostat is primary.

Which thermostat is primary.

PostBy: bighouse On: Thu Dec 31, 2009 8:17 pm

Hi guys,

I have 2 zones ( first floor, and second floor). the first floor thermostat wires are hooked directly to aquastat on EFM. the second floor thermostat wires are hooked into the R845 relay. When both thermostats call for heat, the second floor takes precedence. I would like that reversed..Should i just hook second floor thermostat wires to aquastat and hook first floor thermostat wires to R845 relay? Thanks for your help.
bighouse
 
Stove/Furnace Make: efm
Stove/Furnace Model: 520

Re: Which thermostat is primary.

PostBy: Sting On: Thu Dec 31, 2009 9:59 pm

The only call for heat that ever should stop other pumping would be a call for Domestic Hot Water Production --- IF the appliance we so undersized that it could not produce both call for heat and DHW simultaneously.

Now -- where did I leave that party hat????
Sting
 
Other Heating: OBSO Lennox Pulse "Air Scorcher" burning NG

Re: Which thermostat is primary.

PostBy: bighouse On: Fri Jan 01, 2010 9:28 pm

Hi, Still can't get first floor circulator to come on if both ( first and second floor) Thermostats call for heat. Second floor circulator takes precedence. Any help?
bighouse
 
Stove/Furnace Make: efm
Stove/Furnace Model: 520

Re: Which thermostat is primary.

PostBy: Sting On: Fri Jan 01, 2010 10:18 pm

Does each circulator have its own relay as on page 4?

http://customer.honeywell.com/techlit/p ... 5-6571.pdf
Sting
 
Other Heating: OBSO Lennox Pulse "Air Scorcher" burning NG

Re: Which thermostat is primary.

PostBy: bighouse On: Sun Jan 03, 2010 11:26 am

Each circulator does have its own relay. First floor circulator comes directly from EFM 520 aquastat. Second floor circulator comes from R845 relay. Is that what you mean? Should I connect both zones thermostat wires to the R 845 relay?
bighouse
 
Stove/Furnace Make: efm
Stove/Furnace Model: 520

Re: Which thermostat is primary.

PostBy: Sting On: Sun Jan 03, 2010 12:02 pm

Well -- It depends!

I wouldn't have a zone connected to the coal boiler aquastat. I would connect the T1 and T2 on the coal boiler aquastat with a jumper and let the boiler idle fire as it needs --- and react (hi fire) to energy draw as the building requires.

I would wire each t-stat to its zone pump via the relay of course to control energy flow out to the zones as its called for.

But I am simply a figment of the public internet - Your mileage may vary.

I would also have an outdoor reset wired in place of the jumper I describe above to command the boiler temperature to degree day load.

Then there is that pesky Balancing of the flow out to the zones :lol: - but lets get the house heating wiring corrected first.
Sting
 
Other Heating: OBSO Lennox Pulse "Air Scorcher" burning NG

Re: Which thermostat is primary.

PostBy: bighouse On: Sun Jan 03, 2010 12:39 pm

Sting, thanks for your help. I will wire both thermostats as you said and go from there. Thanks again. Happy New Year.
bighouse
 
Stove/Furnace Make: efm
Stove/Furnace Model: 520

Re: Which thermostat is primary.

PostBy: Sting On: Sun Jan 03, 2010 4:35 pm

Lets not forget -- By re-commanding the pumps as I suggest -- You gain control but you have lost your "heat dump"

May I suggest you address that before the heating season moderates.
Sting
 
Other Heating: OBSO Lennox Pulse "Air Scorcher" burning NG