Phantom L8148E Issues.... It is so very interesting...

tdipietro

Hello smart boiler people of the world... I come to you with an issue that has me perplexed and my wife ready to throw a few pots and pans at me....

Burnham Boiler RV5NSL-L2. Controller L8148E


Once or twice a month, we will wake up to no heat... if I am home.. I break out the multimeter, grab the troubleshooting tips to check for 24 Volts between the various contacts... as soon as I do... I hear a click.. then the direct vent fan comes one.. the pilot light is then lit and heat is restored... sometimes it is an immediate click when I check for voltage between W and B2, other times.. I make it 2 or 3 steps down to B and B2... this has happened probably 20 times over the past 2 years.....

Unfortunately... my wife is not a fan of the multimeter... so if I am not home, I have her power cycle the entire boiler... which sometimes works... other times... I get colorful text messages that I need to call someone to fix this.....

Where I am lost is... how random this issue is and why it is corrected when the multimeter is applied...

ratio

Sounds like a poor connection somewhere. Check/tighten all the terminations & splices/wirenuts. What stat? The contacts in it could be marginal. Maybe replace it with a cheapie & see if the problem still occurs.

GBart

Call a pro

What do you do for a living? Can I go online and circumvent your services and get them for free?

tdipietro

@GBart is a licensed required to swap out a control board...... also.. ironically... in my line of work... you can go online and get a similar service for free... however my service is better just not everyone is willing to pay for it...

GBart

depends on the state but usually a homeowner is allowed to do anything on their home, they still have to follow codes and pull permits

what you're asking for is decades of training and experience for free, it doesn't matter if a license is required, also you're at a point where guessing is over, an experience tech needs to look at this, or you could change a bunch of parts and see what happens,checking variously at points for voltages isn't telling you anything other than yeah, there's voltage there, but should it be? and if it is does it matter?

ratio

Huh. I didn't get that impression at all, it just sounds like a real head scratcher, not a 'fix my stuff for free dude" type of request. Maybe it really is time to call a pro, but we all know how well that can work out, and once you're vested in finding a problem it's sometimes hard to extract yourself from it.

Also, I have been known (Shhh. Don't tell!) to disobey SWMBO for no other reason than it pisses her off…

Grallert

GBart said:

depends on the state but usually a homeowner is allowed to do anything on their home, they still have to follow codes and pull permits

what you're asking for is decades of training and experience for free, it doesn't matter if a license is required, also you're at a point where guessing is over, an experience tech needs to look at this, or you could change a bunch of parts and see what happens,checking variously at points for voltages isn't telling you anything other than yeah, there's voltage there, but should it be? and if it is does it matter?

Kind of the point of this sight I think. Come ask questions hopefully get some answers. I'm here to offer insight if I can. I got nothing here except maybe a lose wire or wire nut.

SuperTech

L8148E aquastats are known to be problematic. Do you have a flue damper that opens and closes when the burner turns on and off? If you do the plug that connects the flue damper to the aquastat can be the problem. I've seen several that will function/malfunction when the plug is jiggled.

I recommend replacing it with a different model aquastat. Most of the time I'll replace a 24 volt aquastat with the Honeywell L7224U digital aquastat and wire a 24 volt transformer on B1 and B2. I don't think it will work if you have a flue damper

EBEBRATT-Ed

@tdipietro

If it's happened 20 times and always when your poking around in there check for loose wiring connections.

If it keeps happening you have 2 choices:

Call a professional

or

Take a chance and replace the control could have bad contacts in it.

Not a fan of changing parts for no reason though

Erin Holohan Haskell

GBart said:

What do you do for a living? Can I go online and circumvent your services and get them for free?

Let's keep this respectful, @GBart. This site is here so that people can help one another.

tdipietro

@EBEBRATT-Ed To clarifiy... it is 20 times over the course of a year... and once I "poke" around with the multimeter.. the solenoid clicks... the fan comes on, the pilot is lit and we have heat..... going to check for loose connections and check the damper as suggested above...... the problem with calling someone... in my experience... they can't troubleshoot something that is working..... if the boiler didn't come on after just one or two voltage checks... I would happily call someone in..

One thought... I will have to start tracking where it seems to happen when it drops into the single digits...

tdipietro

GBart said:

depends on the state but usually a homeowner is allowed to do anything on their home, they still have to follow codes and pull permits

what you're asking for is decades of training and experience for free, it doesn't matter if a license is required, also you're at a point where guessing is over, an experience tech needs to look at this, or you could change a bunch of parts and see what happens,checking variously at points for voltages isn't telling you anything other than yeah, there's voltage there, but should it be? and if it is does it matter?

I will pass your note on to the manufacturer and ask them to remove the troubleshooting section from their manual.... since they supplied a flowchart tied to each voltage test.

GBart

Erin Holohan Haskell said:

GBart said:

What do you do for a living? Can I go online and circumvent your services and get them for free?

Let's keep this respectful, @GBart. This site is here so that people can help one another.

I am, just making a point, there comes a time to call a professional.

GBart

tdipietro said:

GBart said:

depends on the state but usually a homeowner is allowed to do anything on their home, they still have to follow codes and pull permits

what you're asking for is decades of training and experience for free, it doesn't matter if a license is required, also you're at a point where guessing is over, an experience tech needs to look at this, or you could change a bunch of parts and see what happens,checking variously at points for voltages isn't telling you anything other than yeah, there's voltage there, but should it be? and if it is does it matter?

I will pass your note on to the manufacturer and ask them to remove the troubleshooting section from their manual.... since they supplied a flowchart tied to each voltage test.

well if you read their manuals they all have a spot where they say

Installation, maintenance, and service must be performed only by an experienced,skilled and knowledgeable installer or service agency.

All heating systems should be designed by competent contractors and only persons knowledgeable in the layout and installation of hydronic heating systems should attempt installation of any boiler.

SuperTech

Have you tried replacing the aquastat? It's worth a shot at this point.

HVACNUT

Well the inducer fan is running so we know theres 24v to the GP relay and the 1-3 N.O. contacts are closed. You need to check if the 4-6 N.O. contacts are closing. If your meter has min/max, you can capture an open circuit.
That's the safe check.
N.O. out of the pressure switch goes directly to 24v on the ignition control. If that pressure switch does not close or erratically opens and closes (a manometer would be great here), then dont assume it's a bad pressure switch. It could be a serious intake or venting issue. Then its Pro time.
The Honeywell R8222U GP (like Jeep, General Purpose) relay does have a habit of loosening resulting in poor contact. The brown section comes out. Make sure its fully seated

tdipietro

This thread from a few years ago... is very interesting... am I moving the board just enough when I test to make the connection... hmmm

https://forum.heatinghelp.com/discussion/comment/1268126/#Comment_1268126

SuperTech

> @tdipietro said:
> This thread from a few years ago... is very interesting... am I moving the board just enough when I test to make the connection... hmmm
>
> https://forum.heatinghelp.com/discussion/comment/1268126/#Comment_1268126

Yes, it's quite possible that is the problem. This is exactly what I was referring to in my previous post on this thread. It's a well known problem with the L8148E, that's why I recommend replacing it with a different model of aquastat if possible.

delta T

I would guess it needs to be replaced, I have spent hours pulling my hair out trying to figure out what is wrong, only to take it back to the shop after replacing one and find the solder connection somewhere on the back of the board pulling off just a little bit and causing intermittent problems. The slightest pressure on the board can make it work, or make it fail. If its over 10 or 12 years old, I would call it a day and replace it. Do yourself a favor and replace with something better!

tdipietro

Well ladies and gentlemen.... @GBart that includes you as well, you can come back into the circle.....

It appears to be the molex plug, as described in the post from @Tim McElwain in June 2012.... when the heat didn't come on a few minutes ago.. I left the multimeter in the drawer and gently pressed the molex plug and got the immediate solenoid click and the boiler fired up.... so my previous multimeter tests were simply rocking the board enough to engage the contacts....

Time to replace Mr L8148E