Beacon Morris BRT105 to Johnson Controls A419 wiring question????

[rpludwig]

new here, and from a quick look at this forum, you folks may have a solution to my problem.

Shop/cold weather application
Beacon Morris BRT105 propane (110BTU) heater
Installed w/Honeywell RTH2300B1012 thermostat by hvac contractor
All works well till temps go below freezing

Application is to heat the shop to mid 50's only when working, otherwise, shut down, no heat needed (save propane).

The installed stat has a LO of 32*, and then is inoperable and displays LO with fresh batteries, thus the heater cannot be turned on via the stat.

Several folks recommended a Johnson Controls A419 (24volt model) for this application since it is not affected by low temps and has a wide range of -30* to
+212*.

Purchased and connected per instructions, pretty straight forward.
Terminals on heater are R (24v+), G and W1. Multimeter confirms 24vac from heater (R to ground and R to G).
Once connected to the A419 (R to T2, G to T1), energize the heater, the A419 shows alternating error code C03 then ambient temp, repeatedly, and heater does not turn on.

Setpoint is set at 50*, both jumpers are shorted per heat instructions.

Meter across T1 and T2 shows voltage drop to 14.5vac when energized, although 24vac is coming in.

Call to Johnson Controls cannot figure it out (although they have been quite helpful and patient)...I have yet to contact Beacon Morris, however thought you experts may have been thru this b4 and have some insight.

Tried the hvactalk forum, no diy'ers allowed, although one reply sez wired wrong...(G to t1).

Thanks in advance....great forum here!!!

Ron

 

[anthony666]

jump t1 & t2 on the heater .. report back

 

[rpludwig]

assume you refer to R & G on heater? (heater has R, G, W1, thermostat has t1, t2)

On heater:

R to G reads 24v.
R to ground reads 24v
G to ground reads 0

 

[anthony666]

no .. i read it as you having t t on the heater .. if that's available a dry contact between those terminals is a heat call

to turn it on you need 24 volts between r & w terminals .. so jump that .. if that makes the unit fire then the issue is on the t stat side of the equation

 

[rpludwig]

http://www.pexsupply.com/Johnson-Co...le-Stage-Digital-Temperature-Control-24v-SPDT

this might help...if you click on manuals/user guide, then go to fig 9 top of pg. 6, 24v wiring diagram...

question remains, from the htr I have R, G, W1

power to the stat is supposed to go to t1 and t2 according to JC.

thus, what goes to what?

follow up is TB2 connections, looks like a jumper from C to T2, and then something to NO (normally open) on TB2.

I really appreciate your help on this, and apologize in advance for asking so much!

Ron

 

[rpludwig]

Still stumped on this one, but will wait for my hvac guy to figure it out! In the interim, I can use the supplied residential stat by reversing the battery polarity and reinsert properly to reset the stat and override the LO temp cutoff.

Eventually will get the JC A419 hooked up properly in place of the Honeywell.

Thx folks for your help on this!

Ron