Carlin 400N repair or replace?

PEvans

This burner is on a Smith-Mills 100-110-150-1500 hot water boiler with six sections. Probably dates from the 60s.

The condition of most of this system is unknown; I inherited it and I'm just bringing it up.

The orange wire voltage on the burner primary control (R8184 g 4009) reads 0.7VAC and does not seem to switch, so I'm going to guess the primary control is bad.

The CAD cell seems to respond to light levels.

I see almost no information about this particular burner on this forum or on the internet. Further, it isn't that clear to me how to take it apart to test the motor and the ignition transformer -- the Jefferson Electric ignition transformer is mounted on the side of the burner sort of underneath the motor.

So my question for the Wall is, should I replace the primary control and continue to evaluate, or just replace the entire burner with something newer and better supported?

EBEBRATT-Ed

The Carlin 400N (I am trying to remember) I think it is a slow speed flame retention burner but I think there were some variations in the model # so I am not sure.

I know those boilers well and they are pretty good. That burner has all pretty much standard parts so you can get motors, pumps and transformers etc for them.

That burner and boiler are probably 1960s ish so you are probably due for an upgrade


That being said, if the burner and boiler are in good shape you could fix it up have it serviced and run it for a couple of years while you plan for it's replacement...winter is coming.

If you want to see if i will fire and run JUMP the black and orange wires together on the primary control.

DO NOT LEAVE IT THIS WAY IT IS ONLY FOR TESTING AND DON'T UNDER ANY CIRCUMSTANCES WALK AWAY FROM THE BOILER AS YOU HAVE NO SAFETY CONTROL, NO FLAME SAFETY NO NOTHING. DO THIS AT YOUR OWN RISK and if you not comfortable doing this call an oil service tech to evaluate the burner and boiler

THIS IS FOR TESTING PURPOSES ONLY

Pictures will help

Steamhead

@EBEBRATT-Ed , you nailed it. Here is more info on those early Carlin flame-retention burners:

https://docplayer.net/54247362-Wat-e-r-iianfdbooi-oil-iieater-s.html

@PEvans , don't replace that primary with the same thing. Its 45-second trial for ignition period no longer meets Code. Carlin, Beckett and Honeywell make much better primary controls- 60200, GeniSys and R7284 respectively- with 15-second trials for ignition, and these newer controls also shut off the ignition once the flame is proven.

I doubt a new burner would save much. This Carlin should produce at least 10% CO2 with zero smoke when set up correctly.

PEvans

Do you agree that the primary control is faulty, or am I testing it wrong? @Steamhead Thanks for the tip on an upgrade.

If I jump across the controller, can I use this to confirm that the ignition transformer is working?


Some pictures follow. As you can see, the ignition transformer is sort of under the burner motor. The nozzle and electrodes are behind the steel cover at the bottom.


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EBEBRATT-Ed

@PEvans

as i posted above you can bypass the control FOR TESTING PURPOSES ONLY. Do not leave it unattended in this condition.

Yo can do this to confirm that the burner will light and run which will test the burner, ignition transformer and fuel pump and oil supply

If the burner runs then get a new upgraded primary control as @Steamhead suggested

If you are not comfortable doing this call an oil technician in

PEvans

So thank you for the suggestions. I jumped the orange to line (energizing both the burner and the ignitor) and the unit did fire up and run.

PEvans

I also noticed that the TT terminals on the primary control don't change with a call for heat; they read zero resistance either way. There is a Honeywell RA832A that switches and turns on the circ pump on a call for heat. Is this all as it should be (sorry if this is a dumb question).

EBEBRATT-Ed

It looks like you have 3 2 wire thermostat cables going into the RA832A relay.

Do you have a tankless heater for DHW? I assume you do

One cable comes from your thermostat and should go to the T -T terminals on the relay. This starts the burner and the circ pump

One cable comes from the aqaustat that would go to x-x on the relay

The cable that goes to T_T on the cad cell control should also connect to x-x on the relay

When you wire up the cad cell control the way it should be white-neutral, black to hot from the limit control & relay and orange to the burner motor and transformer and white from the motor and white from the transformer to neutral with power to the control 120 volts on the black & white you jump T &T on the control

If the thermostat and or aquastat are calling the burner should start. If not the cad cell control is likely bad unless the cad cell is seeing light which it shouldn't be

PEvans

@EBEBRATT-Ed, this was super helpful. I didn't think about the fact that the circ pump and burner would run independently, and I think that is how this system is set up. The circ pump will respond to the thermostat, and the burner will respond to the aquastat (and maybe the thermostat also). The system may be set up to maintain the boiler temperature as read by the aquastat even if the thermostat is not calling; not sure.

Anyway, the primary control was not making the burner start. However, the physical relay in the RA832A was sticking and it works now.

Working with a tech, not just me, we charged the system with water, started the boiler and bled the radiators. We found one pipe with a freeze break, fortunately it could be isolated. I have one radiator that seems like it is bled but does not want to heat up. The rest, including the ignitor and CAD cell, is working.

Thank you all for your assistance!!

EBEBRATT-Ed

@PEvans

I am glad you got it running but I would be very cautious about that cad cell control. If the relay sticks closed bad things can happen and you will be relying on limit contros and safety controls to shut the burner down.

I recommend you replace it

PEvans

@EBEBRATT-Ed

Thank you for the caution; good point. This boiler also has no LWCO. Is there a way I can add that?

EBEBRATT-Ed

@PEvans

yes, it needs to go in the boiler above the safe water line or above the boiler in the piping. Use a probe type low water cutoff. If in the piping you need a big enough tee or fitting to accept the probe. Taking out an elbow and replacing it with a tee (probe in the run of the tee ) works as well