Problem with Honeywell L8148A aqua stat

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Old 03-17-14, 08:15 AM
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Problem with Honeywell L8148A aqua stat

My Dunkirk boiler is controlled by a Honeywell L8148A aquastat. The boiler is hot, but the pump is not running, so hot water is not circulating to the baseboard radiators. When this happened before, a gentle tap on the relay with a piece of wood solved the problem. But not today.

When the thermostats are turned off, I have 27 volts AC coming out of the transformer and 120 volts at L1 and L2.

What should I check next?

Thanks for any help you can offer --

Andy
 
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Old 03-17-14, 08:35 AM
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Hi Andy,

Sounds like a typical case of a cracked solder connection where the switching relay is soldered to the PC board.

If you know that the relay is pulling in when the thermostat calls, and the burner is starting with no problem then obviously the trouble is between the relay and the C1 and C2 terminals.

If you own a soldering iron and have skills at soldering electronic boards, you can give that a shot... find the cracked solder, and heat and reflow with fresh solder... else, replace the aquastat.
 
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Old 03-17-14, 09:18 AM
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more about Honeywell aqua stat

I have a soldering iron, but can't see where to solder. I tried to upload a photo, but don't know if you can see it. You probably know what these look like. Do I solder all around the square base of the relay where it touches the circuit board?

I don't know what you mean by "the relay is pulling in." If it was, the pump would turn on and I would have heat, wouldn't I?

I nudged the relay with a stick again and the system ran for just a few minutes, then turned off.

How expensive is a new aqua stat? How hard is it to replace? Would I need to drain the system?
 
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Old 03-17-14, 09:47 AM
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Do I solder all around the square base of the relay where it touches the circuit board?
No, not at all.

In order to access the solder side of the board you would have to remove the aquastat from the boiler, carefully removed the pc board from the case, and on the reverse side is where you would have to re-solder the connections to the relay terminals.

I don't know what you mean by "the relay is pulling in." If it was, the pump would turn on and I would have heat, wouldn't I?
That square thing... black and silver... on the right side in the photo is the 'relay'. A relay is an 'electromagnetic operated switch' that turns on when power is applied. When I say 'pulls in' what I mean is that when the thermostat calls for heat, you hear a 'click' and it's that part that is being activated to power the burner and circulator.

How expensive is a new aqua stat? How hard is it to replace? Would I need to drain the system?
That aquastat can be had for under $150:

L8148A1017 - Honeywell L8148A1017 - High Limit Horizontal Mount Aquastat Relay, 8F differential

Relatively easy to replace, given a person who can label wires so they go back on the same place they came off.

No, you do not need to drain the system.

By the way, you see that green and yellow wire at the bottom of your picture? That wire is not supposed to be just 'floating' around inside there. That should go to a ground screw (green) on the case of the aquastat.
 
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Old 03-17-14, 11:37 AM
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spot-on diagnosis!

I found one broken connection, re-soldered it, and house is warming up nicely. Thank you!!

Like most contractors, I am a jack of all trades. With 8 inches of snow here, I had slim hopes of getting my heating guy here today, so I needed to tackle this myself.

Good catch on the loose ground. I would have caught that when re-wiring, but I'm impressed that you spotted it in the tiny photo.

I made one mistake: I forgot to replace the cardboard insulator behind the circuit board. If you were in my shoes, would you undo the connections to put that back in?

Andy
 
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Old 03-17-14, 12:34 PM
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Good job Andy!

If you were in my shoes, would you undo the connections to put that back in?
I dunno... might it be possible to leave everything connected and just lift one side of the board enough to slip the insulator in from the side?
 
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Old 03-25-14, 03:29 PM
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Hi, I am having the same problem. I had someone actually make me replace the circulator pump TACO 007- F5 for no reason the issue is still there. I have to manually pull the lever up to have the heat going. So i pulled it up and placed a piece of wood in between to have it running. But i notice that it runs for 5 mins and the system heats up and the boiler shuts off. So now the boiler keeps running for short period of time and then shuts off. I do feel the vibration on the pump so i am guessing it is distributing the hot water. The house is getting heat. now is this safe to leave the piece of wood to lift the lever? how can i solve this issue? Please help i already spent $500, with this incompetent repair man who couldn't detect the issue and my issue still exists.
 
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Old 03-25-14, 03:43 PM
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Please help i already spent $500, with this incompetent repair man who couldn't detect the issue and my issue still exists.
Wow... all that to replace a $75 pump, sorry for ya man.

But i notice that it runs for 5 mins and the system heats up and the boiler shuts off
You mean that the BURNER shuts off. It's doing this because the water in the boiler is getting hot. Have you looked at the temperature gauge? It will probably be around 180F.

is this safe to leave the piece of wood to lift the lever?
What it amounts to is the system will deliver heat constantly to the home and eventually it will be so hot in the home that you will be stripping nekkid and opening the windows.

Is it SAFE? as in, will the house burn down? No, the house won't burn down. It's not UNsafe in that respect... it's not WISE, or good practice, but you need heat, right?

how can i solve this issue?
You've either got to have some skills to troubleshoot the problem and do the repairs yourself, or you have to call someone with same.

Can you tell us if your system is ZONED? In other words, do you have more than one thermostat in the home and are there electric zone valves on the pipes?

Do you own and know how to use a multimeter?

Can you tell us the make and model of the boiler and the model of the aquastat?
 
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Old 03-26-14, 06:54 AM
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Thanks NJ Trooper for your reply.

The Aquastat: http://s3.pexsupply.com/manuals/1287..._PROD_FILE.pdf

L8148A, Single zone, only high limit ( no low limit ), boiler is Peerless cast iron. I am going to attach picture of my whole system.

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Now some question. When i pull the lever, the silver piece that is marked on the diagram as "Switching Relay", What is the function of that, does it turn on the burner or it turns on the circulator? What activates that lever to pull? is it the thermostat call for heat activates that lever? as i said i am currely keeping it lifted via a pice of small wood.

Next if the thermo stat is not calling for heat then the boiler should not run in my case or the fact that i have the lever pulled it will run till the max temp reached?
When the boiler shuts off, the temperature in the temp reading attached to the boiler shows it reached the temp of the aquastat dial ->i set that dial to 200. The burner will stop and i do see it stopping.

I notice this boiler and panels gets exteremely hot after running for few minutes, while the good one runs for 20mins and doesn't get that hot. Why is this happening, I do feel the vibration very slight on the pump, so i know pump is working and it is a new pump.

I do not have a multimeter, but i think i am going to get one when i have some time.
 
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Old 03-26-14, 07:48 AM
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the silver piece that is marked on the diagram as "Switching Relay", What is the function of that, does it turn on the burner or it turns on the circulator?
That part is a DOUBLE POLE (meaning that there are two individual sets of contacts) part and it controls BOTH the burner AND the circulator.

What activates that lever to pull? is it the thermostat call for heat activates that lever?
Yes, the thermostat is what activates that relay to pull in.

Next if the thermo stat is not calling for heat then the boiler should not run in my case or the fact that i have the lever pulled it will run till the max temp reached?
By 'wedging' that relay in the closed position, you are bypassing and over-riding any calls for heat from the thermostat.

As long as that part is wedged closed, the circulator pump will continue to run constantly and the burner will cycle on and off as required to maintain the high limit setting of the control.

When the boiler shuts off, the temperature in the temp reading attached to the boiler shows it reached the temp of the aquastat dial ->i set that dial to 200. The burner will stop and i do see it stopping.
Turn the aquastat setting down to 180F , you definitely do not need 200F water to heat your home.

I notice this boiler and panels gets exteremely hot after running for few minutes, while the good one runs for 20mins and doesn't get that hot.
I don't understand what you mean. Are you now saying that you have TWO BOILERS ? Is this a multi-family residence? Are you the OWNER of this equipment?
 
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Old 03-26-14, 08:06 AM
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Yes, this is a multi family house, 3 floors in the house, each floor has its own boiler with the aquastat.

thanks a lot for explaining this. I will lower the temp to 180F. Not sure, is it time to replace the aquastat?

Another question, is it possible to have the burner come on and run for few mins but not the Circulator. I think that relay switch the circulator end is somehow not contacting well, because the boiler comes on with the thermostat calling but circulator not coming on unless i do the manual switch.

Is there a way i can fix this without taking out the whole aquastat, i am not expert but what would i look for to make this contact stable?

Pipe questions. There is one cold water pipe which is cold and sometimes gets warm but not hot, but the pipe connected to the circulator is hot which is pushing the hot water out, there is anoehr pipe that comes from the top of the boiler that is very hot also, is that also sending hot water out?
 
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Old 03-26-14, 08:17 AM
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Yes, this is a multi family house, 3 floors in the house, each floor has its own boiler with the aquastat.
You did not answer if you are the OWNER of the building and thus the equipment.

There are certain laws in your state that require only LICENSED PERSONS service and maintain heating equipment PARTICULARLY in multi-family homes.

In view of this, I think it best that you find a qualified technician to repair the boiler for you. We would be remiss to continue helping in view of the possible liability issues. Sorry...
 
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Old 03-26-14, 08:21 AM
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YES I am the owner of the home and my family and relative occupy the whole house. so it is all within family .
 
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