Aquastat problem in Revolution 6

wayne_20

We have a 6yr old Revolution 6 with a L8148E-1299 aquastat.

Three times in the past week the boiler wouldn't start. (Circulators on, no heat) Started following the troubleshooting tree in the boiler manual. When I press near the B1 connector and the plug connector above it in the Aquastat the blower starts and the boiler comes on.

The plug connector below the high limit dial and the B1 and B2 connector is a 6 hole plug (2 rows of 3 holes) that has a wire joining the middle holes. I don't see this in the Aquastat docs. What is this plug?

It seems like I have a loose connector in the aquastat. The first time this happened the blower would turn on and off as I wiggled the B1 connector. When it happened tonight I pressed on the 6 hole plug connector and the blower kicked in. So I'm not sure if it either of the connectors or just the fact that I'm applying pressure in that area of the aquastat.

Anything else it could be? Just wanted to get a better understanding before I meet with a plumber to explain the problem. Is replacing the aquastat a normal course of action?

Thanks.

Wayne

Dan Sedens

It is possible to fix,

if you know what you are doing. I have come across many of these problems. Incidently only on the revolution. I don't believe it is a Burnham issue although it seems strange that I find it only on the revolution. The 6 prong adapter is a jumper to start the inducer fan. No fan = No heat. If you are knowlegable about electrical soldering. You could disconnect module. Remove board. Resolder joint behind 6-pin jumper. You should be able to see which one is moving. I've done this many times and works fine. If you do not feel comfortable(have no experience), I would not recommend it!! Hire a pro in your area. Have him replace the controller or solder the board. This controller is the brains of the operation. Not something to practice on. The part is fairly affordable , although new honeywells have different wiring harnesses which will need to be rewired.Hopefully, Tim will jump in on this.

wayne_20

Verified it is the fan jumper

Thanks for the reply. It failed again this morning. It definitely is the fan jumper. I've propped it up to keep the electrical contact going.

My current theory is that when the boiler is off for long periods of time in the night or during the day when we are at work the solder joint looses contact due to temperature contraction and it fails until I prod it back on place.

Would my plumber know how to just replace the controller board ? Sounds cheaper than replacing the whole Aquastat.

Unknown

Wayne

The plug you are referencing is a jumper we have installed to bypass the inner circuitry of the control in reference to what that jack is for and that is not the fan. The fan is brought on by the switched burner circuit or B1 - B2. The L8148E is a control that can be used in a variety of applications and comes equipped with the ability to control a vent damper by means of that 6 pin jack. Since the Revolution does not use a vent damper, the jack would normally have an internal resistor connected to take the place of what the end switch of the damper would do if it were installed and operating. We had some difficulties with that internal resistor not functioning as desired so we chose to have the jumper plug installed to jump out the two center pins of the jack. I would first check the integrity of the jumper plug before anything else. If the pins are not making good contact that may be the problem. Simply pull the plug out and make sure the two pins are making good contact and tweak them a little if neccessary and plug it back in.

I need to warn you that removing the board from this control and attempting to make modifications to it by soldering and such is not a practice that is condoned or approved by Honeywell at all. Without the proper knowledge and skill of understanding what is on the back of that board, you may be at risk of harming yourself and other occupants and possibly doing harm to other components of the boiler. It may very well be that the solder connection on the back may have come loose, but the board is not a replaceable component. The whole control would have to be changed. No real modifications need to be made to the control other than removing the existing plug-in harnesses from the old control and reconnecting them to the new control. Hope this helps.

Glenn Stanton

Manager of Technical Development

Burnham Hydronics

U.S. Boiler Co., Inc.

wayne_20

Thanks for the reply Glenn.

I'll pull the jumper plug and check the pins tonight. I have a call into the installer and will start the process of getting another aquastat ordered in case it is the solder joint. Right now I'm just propping up the jumper with a piece of cardboard to make the connection happen. So unless it is the solder joint and it completely fails I should be able to operate the boiler.

Wayne

wayne_20

One more question

The part number on the aquastat is L8148E-1299 Is this enough information for the plumber to get the aquastat? I would just rather have him order one up today rather than wait till after he looks at the boiler tomorrow to save time.

Wayne

Unknown

Wayne

Check your e-mail or call me at my office and I'll discuss another simple alternative to correct this with you. (401)789-1899

Glenn Stanton

Manager of Technical Development

Burnham Hydronics

U.S. Boiler Co., Inc.