Burnham MPO-IQ restart problem

gregarsenault

Hi- new to this site.
the subject boiler had an aquastat error.
I reset the option card, now everything says stand by- but the burner doesn’t even try to light. With this system, there is no reset button on the Honeywell R7284 primary control. 

When I press the primary controls “I” button , it says TT closed ( makes sense since it is using another controller) and 
L1 open…that’s the part I don’t get. Have powered on/off several times with no success??

Big Ed_4

Which control did the aquastat error code pop up on ?

HVACNUT

How is it saying L1 open when it needs L1 (120 VAC) to tell you that? Are you sure it doesn't say "Limit open"?

There's no reset on the main board? 

Do you have an electrical meter?
There should be constant 120 volts to the primary L1 and the "oil boiler control" L1. 
Like you said, TT is internally jumped in the primary. When TT closes on the main board, it sends 120 volts to Red (Limit) on the primary through the temperature sensor. 
Can you jump TT at the oil boiler control or the main board? 

I'm not real familiar with Burnham and their cards. Is what they're calling the aquastat actually the "Boiler Limit Temperature Sensor" in the diagram? That could be the issue. If the sensor is open, it won't send power to the primary. 
Is there an indirect water heater installed?

gregarsenault

You are correct- it said limit open, not L1. I have 120V where I should. The TT at the primary has been bridged, so has the option card  board. There is no reset on the board, you have to walk through the process on the option card… which I had to do for the aquastat option card.
what I did this morning is to jump the T /T3 in the main board and it fired right up… which tells me that sensor is bad…and I think you are correct- that’s what they call the aquastat.

Big Ed_4

Don't jump out that sensor , "Shut the boiler down" until you can replace it...

HVACNUT

gregarsenault said:

You are correct- it said limit open, not L1. I have 120V where I should. The TT at the primary has been bridged, so has the option card  board. There is no reset on the board, you have to walk through the process on the option card… which I had to do for the aquastat option card.
what I did this morning is to jump the T /T3 in the main board and it fired right up… which tells me that sensor is bad…and I think you are correct- that’s what they call the aquastat.

Please try to be specific. You jumped T,T3 on the Oil Boiler Control, not the main board.
Yes, you basically bypassed the aquastat, so bad aquastat (sensor) or short in the card or wiring. Is there an ohm chart in the manual?

Big Ed_4

The thermistor went bad , Rule number one in this industry .. Don't %$#@ with a limit. ... Trust me ... To see the damage of a boiler blowing up .

Tip for the guys out there , if any steam blasts against any of your clothing , strip real fast .....