Burnham Alpine 210 stops heating water but thinks it's hot

SCan

I bought a new construction home in NH in Oct 2014 that has a Burnham Alpine 210 boiler in basement using Propane and FHA. House is about 4000 sq.ft. has 5 zones, 2 on 1st floor, 3 on second floor, with a 48000BTU heat exchanger in basement for 1st floor and a 60000BTU heat exchanger in attic for 2nd floor.
Everything has been running fine until about a month ago when the heat and hot water would just stop sending heat.
The first time I just reset the boiler and it was fine for a couple of weeks. I figured it was an anomaly until it started happening more frequently, now it's happening every other day. It seems like something is failing. I looked at the front panel and noticed no error codes at the time or in history.
I noticed the supply temp guage was pegged low at 70 and the pipe was cold.
Status showed Supply 128, Return 115, Stack 117, Rate 100%.
Supply/Return Differential screen showed the same numbers as above, but the lines were at the same low point on the chart not showing a differential.
Flame signal 2.5 hour trend line was flat 10 (9.79ua) for 120 minutes.
Boiler, DHW, Central Heat screens also showed the same 128 supply, priority Central Heat, Status: Running, DHW & Central Heat Firing Rate 100%.

As soon as I reset the boiler by shutting off the power at the switch, the supply immediately dropped to 71, Status showed supply & return 71, Stack 68, rate 74%. Temps immediately begin to rise once it starts up and within a few minutes everything is back to what I would call normal temp ranges. See pics below, before reset, immediately after reset and eventually after everything got closer to normal operating temps.

Has anyone seen this situation before? Any suggestions on how to go about troubleshooting this intermittent no error code problem? I'd like to avoid calling the guy that installed the system if it's a simple part replacement. I have my suspicions about what might be the problem, but it would be good to get some help from people that know more about this stuff than I do.

Thanks!

Paul S_3

I had a similar issue it was hi limit sensor sticking open....could be alot of other things ...do u have the installation manual?

SCan

Thanks for the quick response. Happened again overnight. I checked the errors and did notice the high limit was flashing so that sounds like it could be the problem. I'll swap it out and let you know. Thanks again.

SCan

I replaced the boiler high limit sensor but still getting the fault string status error on the Auto Reset High Limit sensor but not the rest in the line. If I had thought about the symptoms and indications a little more before ordering, I would have realized that logically the sensor itself cannot be the problem.
What other troubleshooting steps can I take to narrow down to root cause so I can keep my heat and hot water going? I checked the continuity from the sensor to the control unit to make sure the circuit is good. Not sure what else to check. Thoughts?
Here is a link to a pdf of the manual from US Boiler's site:
https://file.ac/JfW2bqJiSq4/Alpine I&O.pdf

The manual says that if one of the fault string status sensors opens (air press, Auto Reset Hi Limit, Cond Float, Gas Press Sw, LWCO) the rest will show open because they are in series. I can see that each electrical leg of the circuit has a line going back to the main board so that's how it determines what's going on in order to display on the LCD panel. Since only the auto reset high limit is flashing, it can't actually be a real fault with the sensor or the circuit so it must be a problem with the board itself or some way the board is sensing the auto reset high limit is somehow a problem on it's own.

I just don't get how this is apparently randomly causing the board to think the supply, return and stack temps are fine when they are actually not anywhere near the temperature it thinks they are at.

I am going to call the manufacturer on Monday and see if they can tell me how to tackle this problem and get to root cause. I don't want to keep buying parts if they aren't really the problem.

Thanks to anyone that can provide insight into what may be the problem and what to check next. I hate easter-egg hunting as a method and really appreciate a good troubleshooting methodology/approach so if you have one for this problem please share.

Tylermb89

What ended up being the issue? I am dealing with the same thing at the moment and came across this forum. It's been 7 years since this was posted, but figured I would give it a shot!

109A_5

Hello @Tylermb89,

You may want to review the troubleshooting section of the I&O manual.
https://s3-us-west-2.amazonaws.com/catsy.782/Alpine+IO+Manual.pdf

Big Ed_4

It could be the boiler circulator , can you set it to a higher speed ?