Burnham Series 3 cycling for 2 min out of 5 when heat is called for. Insulation layer broken.

eclecticmn

I have a 10 year old Burnham Series 3 hot water boiler for my house.
Everything was OK. Then I noticed it was cycling. It started up, then would shut down with an error saying that the flame detector current was below threshold then shut down and start over again.

I called a plumber/HVAC guy and he came over. He said that the insulation layer over the burners had broken and fallen onto the burners. He said that was unusual and removed the pieces. Said no big deal. BTW I never touched the boiler. Last year I had some tech come over and clean it.

First plumber/HVAC guy must have dislodged the thermostat wire and there was no heat and he did not return my calls. I called the company who installed it long ago, Team Mechanical. They came out and found that wire issue. They said the missing insulation was a huge deal and were looking into it.

Now It is cycling when heat is called for but no error number. It is heating well enough as long as the temp does not get back to minus 18 deg F.

Then the temps fell, New Years Eve came, pipes elsewhere were bursting, people were snowed in, including the HVAC guys and me.

Any thoughts?

EdTheHeaterMan

Ten years ago you got a new boiler, I get that there was a wire that lost insulation So I think that just happened. Someone said no big deal
Then we go back in time and get the heater some well deserved maintenance
After that I lost you because there was a plumber and then a first plumber and then the guys for 10 years ago are back in the picture.

My first question is When did you notice the problem? Last year after the maintenance or just recently?

And were you snowed in on New Years with no heat, with the frozen pipes, or with the HVAC guys?

eclecticmn

Ten years ago you got a new boiler, I get that there was a wire that lost insulation So I think that just happened. Someone said no big deal

Ten years ago a Team Mechanical (TM) from St. Paul installed a new boiler in the old house I was about to buy as the old one froze.

Then we go back in time and get the heater some well deserved maintenance

2022 or 2021 some guy subbed by Home Depot did some maintenance.

After that I lost you because there was a plumber and then a first plumber and then the guys for 10 years ago are back in the picture.

My first question is When did you notice the problem? Last year after the maintenance or just recently?

I first noticed the problem of cycling late 2022. It is possible it happened earlier.
I called a craigslist place that referred me to the "Val" guy, said he was master plumber and HVAC guy. Owned the Val business, outside of town. Seemed real familiar with the boiler. Found the insulation pieces, removed them, tested the boiler, no more error 4, and left. Called him for no heat but he did not return calls.

Somebody perhaps dislodged the thermostat wires. Likely Val. Cannot remember. The wire was in a Wago lever nut that did make contact. So it was not likely their fault.

In a panic I called Team Mechanical. They showed up twice. Found the dislodged thermostat wires, fixed that and left. Then I was not without heat but the boiler was cycling. Everybody was busy or snowed in.

And were you snowed in on New Years with no heat, with the frozen pipes, or with the HVAC guys?

I was only without heat for hours and I panicked and bought new space heaters and used propane tank top heaters until Team Mechanical found the dislodged thermostat wires and got the boiler back to cycling.but with no error code as before.

The insulation pieces looked like wafer board.

EdTheHeaterMan

A little more clear now. By the way.. the snowed in part was for comic relief. I never thought you were snowed in with the HVAC guys. LOL. Good thing you did not have frozen pipes.

Where did you find the pieces of insulation? Near the control/Electrical section (Green) or near the burners (Red)?
And was this insulation something that came off of a wire? If yes, was there any bare wires as a result?
If No then where do you believe it came from?

As far as short cycling is concerned, there are several possibilities. A short cycle can happen at any electrical connection. A wire or switch that is usually connected or Closed Circuit, will open and stop the burner from operating. This could be the thermostat, the limit switch, the flame sensing circuit, the low water cut off... Any number of things can break the electrical circuit. The failed insulation from a wire can be a problem. That is why I want to know if the insulation is from a wire.

If you have a multi meter and understand a basic electric circuit, I can help you locate the source of the electrical circuit that is short cycling.

Are you able to try this? If it is more than you want to do, then you will need a professional to get it fixed. Let me say this: a short cycling heater will not heat your home very well during extreme cold weather, and it will eventually fail. Let me know how you wish to proceed.

Mr. ED

JUGHNE

How about pictures of the insulation board and where it came off of?

eclecticmn

The insulation came from the red area. It was laying on top of the burner tubes in pieces. "Val" pulled the pieces off and may have taken some with him. I took a photo of some pieces. It was like wafer board.

Why will this system eventually fail after cycling like this? What will fail?



I could try to trouble shoot. I have a multi meter. I could read the codes as it cycles through. Starting Wed I have to do remote work at least 8 hours per day so if I do not respond I am not ignoring you.

eclecticmn

The model number is 305NI-G
The status read outs is
Sea 1 (for a few minutes) standby
Sea 18 waiting for damper
Sea 17 self test
Sea 7 flame proving
Sea 8 Running for a couple minutes
then back to Sea 1

Does this cycle to heat the water then stop when it reaches a limit?
My thermostat is calling for heat

If I jumper the thermostat wires at the boiler is that a good test? I recall the boiler tech did jumper something. I see a red and white wire coming into some connections.

EdTheHeaterMan

eclecticmn said:

The insulation came from the red area. It was laying on top of the burner tubes in pieces. "Val" pulled the pieces off and may have taken some with him. I took a photo of some pieces. It was like wafer board.

Why will this system eventually fail after cycling like this? What will fail?

I could try to trouble shoot. I have a multi meter. I could read the codes as it cycles through. Starting Wed I have to do remote work at least 8 hours per day so if I do not respond I am not ignoring you.

Short cycling

I like to think of it like this. When someone makes something mechanical, it will eventually wear out. If you take a piece of tin, and fold it back and forth 20 times or so... it will break. If you don't bend it ever... it will last much longer.
If you have a light switch that you turn on once a day and turn it off once a say It will last longer that the same switch that is operated 60 times an hour. There are just so many times that a switch will operate until it wears out.

Now take a typical heater that is on a thermostat. Every hour it may run for 15 minutes then go off for 10 minutes. Then on for 15 minutes then off for 10 minutes. So it will cycle 3 times an hour.

Your furnace is turning on and off 10 to 12 times per hour. That is more that triple the normal number of cycles per hour. So the ignition control, the gas valve and what ever is actually short cycling will wear out 3 times sooner that one that is operating with normal cycling.

Insulation problem

The insulation is nothing to worry about for the electrical problem. However, that insulation is keeping the flame from making some piece of metal from getting too hot and/or reflecting the heat from the flame back into the fire box for more efficient operation. You might want to get some and replace it so the metal it was covering does not get too hot and burn a hole thru it. Depending on the size/modle number this is the part number you will want to look for If all you need is part number 2J then I would just purchase something like this https://www.supplyhouse.com/Lynn-Manufacturing-1026-Ceramic-Fiber-Board-2300F-Rated-36-x-24-x-1-2-4-Pieces and cut the pieces to size to fit what is missing.

Trouble shooting electrical short cycling

This is very easy. You need to look at the wiring diagram and find the parts on the heater that are represented in the diagram. When the flame is operating there will be 24 Volts to the gas valve. All the safety switches will have zero volts measured from each terminal. when the switch opens there will be 24 volts for a short moment when the flame goes out. If there is no 24 volts at a particular control or limit, then that part is not the cause of the flame stoppage. Move the the next control and test again.
Diagram to follow

eclecticmn

One of the techs said I did not need the 24 v transformer and unwired it.
What should the voltage be across the "TT" terminals when the thermostat is calling for heat?
My thermostat has 2 AA batteries in it. Should the transformer be in series with the thermostat?

This manual is for 305BNI-T and I have 305NI-G
http://s3.supplyhouse.com/product_files/Burnham-305BNI-T-Install-instructions.pdf
OR
https://s3-us-west-2.amazonaws.com/catsy.782/Series+3+IO.pdf

I recall the techs got things started by using jumpers. In the vicinity of figure 7-b on page 14. What did they do?

I just checked the wiring and the wires go from the thermostat to the TT terminals directly, via some wire nuts but no transformer connection.

page 35 says 24 V thermostat provided by others.
page 31 says there is a transformer 4-C on the back of the control panel

page 30 has 4 insulation parts 2G, 2h, and 2J. Could one of those fallen down?

EdTheHeaterMan

the older I/O manual will better match your 10 year old boiler http://s3.supplyhouse.com/product_files/Burnham-305BNI-T-Install-instructions.pdf

One of the techs said I did not need the 24 v transformer and unwired it.
What should the voltage be across the "TT" terminals when the thermostat is calling for heat?
My thermostat has 2 AA batteries in it. Should the transformer be in series with the thermostat?

There is a 24 V Transformer included it the factory wiring. A field installed transformer is not required when using a conventional thermostat (not a WiFi smart thermostat)
When the thermostat is calling for heat, the voltage across T T should read zero volts. When there is no call for heat the voltage should read between 23 VAC and 29 VAC (we will call this 24Volts Nominal from now on)

Here is a simplified set of illustrations of how to determine if a set of contacts inside a control is open or closed.
Switch closed, generator operating, load is operating (light is lit)

In this next illustration the generator is running and the load is connected BUT the switch is open so there is not a complete circuit. However there is a difference in potential electricity on either side of the switch contacts. A meter will read voltage in this situation.This is like reading 24 V at the T T. terminals when there is no call for heat

Finally in this illustration, the switch is closed As in the first illustration. There is no difference in potential electricity on either side of closed switch contacts, so there will be no voltage reading here. This is like reading zero voltage at the T T terminals during a call for heat

I recall the techs got things started by using jumpers. In the vicinity of figure 7-b on page 14. What did they do?

Yes by connecting the T T terminals together, you are doing what the thermostat does. The thermostat is just a switch (like a light switch on your wall) but the difference is that the switch opens and closes at the temperature you set. (within 2° or so.. that is called the differential). when the room is colder than the set temperature the contacts in the thermostat are closed (switch turned on) When the temperature is hotter that the room temperature the contacts are open (switch is off).

I just checked the wiring and the wires go from the thermostat to the TT terminals directly, via some wire nuts but no transformer connection. That is correct

page 35 says 24 V thermostat provided by others. that is because the thermostat does not come in the box with the boiler. the contractor provided it when the new boiler was installed
page 31 says there is a transformer 4-C on the back of the control panel That is correct it is behind the control panel. it is easy to see in the diagram

page 30 has 4 insulation parts 2G, 2h, and 2J. Could one of those fallen down? That is exactly what you see in that picture of the insulation. It is 10 years old and very fragile

eclecticmn

I just thought of something. My son moved out of upstairs. So I turned off many more radiators. In this old house heat rises so the temp is still OK. I have three radiators on normally, with manual control. 5 are turned all the way off, which may mean very low as they are hot water radiators valves I believe. 3 are valved off and taken apart for now. I have the temp set low (63 deg F) in the hallway which is almost never met but the places I live in are OK or even too hot.

Yes, I should put in some TRVs or whatever.

I just wonder if I exceeded some design limit somehow?

eclecticmn

As an aside. This 1915 house is old for this area. Not official historic house but unique for this area. A two story stucco farm house surrounded by apartments. It is seductive. "Save me."

The previous owner was seduced and made almost nothing over the years. The house has a name locally. I get Christmas cards from California addressed to "Grandma's house. "
There used to be a shed with a cow.

EdTheHeaterMan

Your first test is to place the meter on the T T terminals during a StA 8 with the burner operating. The Volts should zero (0.0). When the burner stops, tell me if the volts go to 24 or stay at zero (0.0)

The previous owner was seduced and made almost nothing over the years. The house has a name locally. I get Christmas cards from California addressed to "Grandma's house. "
There used to be a shed with a cow.

Was she related to Mrs, O'Leary. The one with the cow in Chicago back in 1871?

EdTheHeaterMan

The next test will be to observe the flame current. press the ( I ) button to change to the FLA display. This will give you the flame signal number.

eclecticmn

I can't thank you enough for this help.
I ran the wood stove today and so the thermostat was set at 63 deg F in the hallway when I got home from Harbor Freight tonight (I lost my multi meter leads) so I bought a cheap one for $7.
The boiler had apparently not run for a while and got a break from short cycling. The TT VAC was 25 VAC when it was off for that long period.

I set the thermostat higher to 67 to force it to call for heat. TT was around 0 VAC while running. I kept running for a long time, longer than before. Maybe 15 minutes. I set the thermostat to 64 deg F and waited. The FLA value was around 17.5 BTW. After the burners shut off TT was still 0 VAC. Then it short cycled again with the same results of TT 0 VAC. Actually 0.8 VAC. This is weird. Why did giving the boiler a rest result in TT being 24 VAC?

I have to work Thursday so I may take time to reply.

eclecticmn

Yes Mrs. Oleary's cow was in Chicago where my brother lived for a while and where I lived for a while. I am from Wisconsin and people there get upset because the Peshtigo fire on the same day killed far more people but Chicago got all the press.
https://en.wikipedia.org/wiki/Peshtigo_fire

This house has a very thick basement wall which extends 6-9 inches in from the first floor walls so running wires from the basement to first floor is almost impossible. I am sure some old wizard could do it but not me. It might take a hammer drill and masonary bit and more smarts than I have. It also screws with the radiator pipes in the kitchen.

eclecticmn

Above, I mean running wires from the basement to first floor OUTSIDE walls is very difficult.

eclecticmn

Thanks again. I figured out the TT VAC thing. When the wood stove satisfied the set point no heat was called for so 24 VAC. When heat was called for with a higher set point then 0 VAC either during or in between the short cycles because heat was called for. I think and hope I solved the short cycles last night by replacing the pump.

EdTheHeaterMan

So the whole short cycling thing is not a result of the thermostat or the thermostat circuit. If it starts to short cycle again, the flame signal may be the problem. As soon as the signal is lost, the flame will extinguish instantly. The controls will go thru the safety start up sequence and the flame will relight. This will happen over and over as long as there is a call for heat.

To eliminate or confirm this as the cause I would clean the flame sensor. also make sure the ground from the control to the flame sensor is not corroded. Now use the control to monitor the flame signal during the short cycling event. If the flame signal keeps dropping until it finally extinguishes the flame, then you may have a bad flame sensor or flame sensor wire or the control might be defective. If the flame signal stays within the acceptable range, and the flame drops out, then the limit circuit may be the problem. One step at a time to eliminate each component one at a time.

eclecticmn

Thanks again. Maybe I should not have called it short cycling. It ran around 2 minutes out of 5. I think the boiler minus the pump was doing its job. It raised boiler temp from around 165 to 180 then shut down. Thanks to your advice I previously checked the flame current and it was OK. For some reason not enough heat was leaving the boiler.

I replaced the Grundfos UPS15-58FC pump two days ago. There is no more short cycling. I listened to the old pump with a screwdriver. There was a humming or whirring sound plus intermittent scratchy sounds. The new one sounds the same minus the scratches. The DanFoss magnetic cell phone app showed rotation ( magnetic field) on the old one.

I took apart the old pump and there was lots of scale on the check valve. I am soaking it in vinegar right now. If I spin it it will coast for maybe a quarter turn. I am guessing it is near the end of its useful life as it is 12 years old. Just a guess. Should I toss it?

Jamie Hall

Bad bearing. Probably toast...

archibald tuttle

missed the early part of this thread. think @EdTheHeaterMan gets the patience award around here. albeit the responses from Minnesota have attempted to adequately convey the situation on the ground and responsiveness to his recommended diagnosis.

This popoed up a month later because you seem to have found that circulation was the problem. With no codes on the boiler that was my suspicion. Some hints that this might be the case is slow response from the house in warming up or keeping warm (which you might have put off to the boiler cycling rather than to failure of circulatin).

my hands are inured to grabbing reasonably hot pipes but short cycling can recommend attention to circulation and just listening for the pump humming in some way that might be spinning does not do the job. that it is vibrating or humming is not an indication that the pump is actually turning. IIRC you have sizeable mains with teed loads so it seems likely that you were operating a gravity system. It is yet the control strategy i have seen in newer 'smart' pumps but i'm getting to wish that the pump had a pressure transducer at both flanges as testing for a pressure differential is the key way to observe circulation besides grabbing onto the pipes with attention to not burning your hands. you can use a non contact temperature measuring device but what you are really trying to get for a signal is not just a few instantaneous readings, but a 'wave' function feeling the pipe over time for the cooler flush coming down the return from the house after a period of no call for heat followed by a slow warming to perhaps 15 degrees cooler return. given high temps you have to touch loosely always first and then be prepared to remove your hand when hotter water arrives so as to take caution not to burn your hand, but when they talk about manual testers, that is the original test for circulation. If unsure of results you want to move down the feed and return 10 or 15 feet from the boiler as you could get fooled by temperatures that creep without circulation into the near boiler piping. This often requires going to two different places if the fee and return go in opposite directions but, IIRC your feeds and returns are parallel so you have it easy.

Now that you have a new pump it would be a good time to ascertain what that pattern feels and how quickly your returns are warmed to your delta, i.e. the differential between the feed and return that represents the btus that have been delivered to the house so in the future you will have reference point. The other apparatus that you seldom see installed is an actual flowmeter or placing tees with pressure gauges up and downstream of the pump.

and this is perhaps the ideal moment to return to the kitchen circuit that was unresponsive, just double that loop back to itself and see if it circulates as I suggested or, acid test, make temporary connection to the double rad in waiting. (and, still a little confused over the framing near your foundation that seems to be preventing you from getting feed pipes toward the wall where you want to place those radiators permanently. In most cases the floor joists would run onto the foundation so there would be a 7" or 9"–or some irregular number if this older house doesn't have lumber strictly corresponding to contemporary measurements–where you could extend a pipe with a bend on it and then lift the bend through the floor. although in some older construction the foundations rises almost to the level of the floor and there are pockets or a ledge formed for the floor joists meaning that foundation is more intimidating in terms of reaching as far out as desired. even if you can't drill the foundation, if you are dealing with a subfloor and floor adding up to 1.5" or more, you could drill quite obliquely though the flooring and probably split the different between having pipes and radiator out in room vs. over by the wall.

lastly, if I have a pump that was quarrelsome (that's french for: a pain in the ****) I temporarily connect it to 120 and looking into the outlet volute to see if the rotor turns. most of the time, in the case of lack of circulation, I may hear that it hums but i see that it does not turn. i can see that you actually rotated yours and it doesn't sound like you found it bound up and freed it in order to do so but that might confound the results of such a test.

brian

eclecticmn

Thank you. I may post some photos of my mess sometime. I got a hot first in line kitchen radiator but have one bad solder joint and one leaky pex crimp to fix. The second in the series only got warm and has a mystery issue I have to troubleshoot. I ran the pex b the same place as the old 3/4 copper which was a mistake and made a mess. I may repipe with pex a.

The scariest words anyone posted were that if the 3/4 copper and slant fin baseboards did not get warm then 1 inch pex with cast iron radiators likely would work either. I wanted to test the concept. On the 3 cast iron radiators I could not get the bottom plugs out opposite the valve.
I tried lots of liquid wrench and deep creep. I tried a axle nut socket set with 1/2 drive and cheater pipe. The breaker bar curved. I put a torch around one. I tried standing on the cheater pipe but gave up when the radiators moved too much. So my mess includes exiting at the radiator tops. Maybe in summer? Bigger socket set? Stack the radiators to weight them down when I stand on the cheater? Impact socket drive?

Before I installed the third radiator near the third window I wanted to run wire behind the baseboard so I need to use a hammer drill chisel. Why? To carve a channel in the plaster settled near the base of the outside wall. I just wanted to heat my kitchen.

Maybe I should have tried cast iron baseboards given the locations but did not know they existed. Maybe on version 4.0.