Aquastat help

homez · October 29

L8148E-1182 is the old part. The one that replaced it is the L8148E-1265 which has a molex plug

The current gas boiler ( that has the 1182 old model) is using a vent damper with black, brown, yellow and orange wires with no molex plug to the 1182.

Question is do I wire it the same and just use the green wire jumper on the molex plug?

Currently the black damper wire is hooked up to TV and the brown wire to w on the top part of aqua stat. The orange wire is hooked up to B1. The yellow damper wire is pigtail to a red wire which leads to the safety switch on the flue next to the damper. The other red wire is getting pigtail to gas valve. The safety switch has two red wires.

Here are some pics.

109A_5 · October 29

" Question is do I wire it the same and just use the green wire jumper on the molex plug? "

I believe that should work.

homez · October 29

yes the bottom picture is what the current old aquastat looks like without molex plug.

New aquastat has the molex 6 prong plug which it seems on diagram you drew out is connected to points 2 and 3 which I’m assuming is the green wire on molex plug. The diagram you sent on 1265 looks like only 5 prongs? 4, 2, 3, 5 and 1.

Yellow damper wire is pigtail to one of red wire safety switch on flue next to damper. The other red wire from safety switch goes to gas valve wire which is pigtail. Is that accurate? I sent picture on previous message if it.

Here is a picture of 1265 with 6 pin

Thanks for the help

IMG_1955.png

molex plug with green wire.

homez · October 29

also the reason I’m replacing the aquastat is the boiler isn’t firing when call for heat.
1. When call for heat the damper opens.
2. I can feel the circulator water passing on pipe where circulator is.
3. pilot light is on

when I looked at aquastat the transformer looks burnt.

109A_5 · October 29

" The diagram you sent on 1265 looks like only 5 prongs? 4, 2, 3, 5 and 1. "

That diagram is from the L8148E manual, the not needed part was edited out and the annotations for your system were added.

Other than the green jumper wire to complete the circuit to B1 the rest of the molex connector pins are not used since your damper is connected via the wires to the terminals. For a molex connector type damper only 5 wires are used. I did not include your Yellow wire connected to the Red wires since all that would stay the same, although you may have to disconnect them to change the aquastat.

See note at the Red arrow.

" reason I’m replacing the aquastat is the boiler isn’t firing when call for heat. "

The transformer looks fine to me. In this situation, what often happens is the solder joints connecting the relay (in picture below) to the circuit board fail. They can be repaired and actually improved if you can do PCB type soldering. Typically a Plumber or HVAC tech would just replace the aquastat.

homez · October 29

thanks. Part is coming in tommorow and wanted to better prepare myself to change it out. I will just connect the wires the same and leave the molex plug in with the green jumper wire. I didn’t want to fabricate a molex plug on the damper wires but was considering it but not worth the extra effort so overall will just connect damper the same way it currently is.

On my end I’m not comfortable doing pcb soldering. It’s possible I could do it but not sure how clean of a job I would do. Maybe there is an article/video somewhere. I got the aquastat for 325 and putting it in isn’t bad it’s just the molex plug through me off as old was doesn’t have it. A plumber would probably charge 800-1200 (parts and labor) to install a aquastat I would imagine.

EdTheHeaterMan · October 30

There is a wiring harness that you can purchase from SupplyHouse.com that will replace the existing wiring harness and plug into the vent damper 6 Prong Molex on the new aquastat if you are interested. It makes making a wiring mistake next to impossible. Vent damper wiring harness

@109A_5 has covered the proper wiring with you and you just need to follow the replacement wires to the new control. Take more pictures of all the wire connections before you take the old control apart.

homez · October 31

so I replaced the aquastat and it didn’t fix the issue. I decided to look at the micro temp and there was no continuity. I put a jumper wire and the boiler fired up. So the whole time it was just the micro temp rollout switch. 325 dollar mistake. Going to see if a local supply house has this. G4AM0600. TF144C. AJA. I don’t think the Aja is needed as I see this part online but can’t find any ending in AJA.

109A_5 · October 31

The AJA may be a date or other manufacturing code.

" also the reason I’m replacing the aquastat is the boiler isn’t firing when call for heat.
1. When call for heat the damper opens.
2. I can feel the circulator water passing on pipe where circulator is.
3. pilot light is on

when I looked at aquastat the transformer looks burnt. "

I believe item number 2 above is not consistent with a Roll Out sensor failure. So maybe the circulator was actually not running. If the Roll Out sensor failed the aquastat relay should never energize. However I don't think the boiler Make / model was ever stated so we could not verify this with the boiler's actual wiring diagram.

homez · October 31

homez · October 31

When call for heat. The aquastat energized and clicked and then vent damper opened. I put my hand on circulator pipe and could feel water movement. Pilot light was on but burners never ignited.

I took out the 2 leads going to rollout switch next to burners. Put multimeter to check continuity and it didn’t beep. The next step is I put a jumper wire on the two wire terminals and then I called for heat and the boiler fired right up. I shut it off and tried it again and fired up after a 2nd try also. So hopefully I can replace this micro temp rollout and be done with it.

109A_5 · October 31

I can't find any info on that boiler, may be an age related lack of info. Is there a wiring diagram on the unit ?

Anyway it looks like you found the actual problem and at least that safety limit is after the aquastat relay.

homez · October 31

yeah it’s a old boiler that was put in 19-22 years ago. I didn’t see any wiring diagram. I am starting to wonder why the fuse went out or maybe it was a one off which caused it to go out. I will try to clean the burners before putting the new rollout switch in.

109A_5 · October 31

When the burner starts up is there a roll out issue ? Excessive flame coming out of the burner getting to that thermal fuse ?

HVACNUT · October 31

Maybe have a look at the burners and heat exchanger and chimney base. Is there proper draft? Is there enough combustion air?

homez · October 31

I will take a look at the burners later today and see if there is any rollout. The micro temp fuse I can only find locally 122 degree Celsius one and not the original 144 degree Celsius one. They are saying the 122 works.

when you say chimney base are you talking about the door at the bottom of the chimney floor (basement level) or at the top of the chimney area at roof level?

Overall going to clean any ash that has fallen to bottom of chimney basement level (this was cleaned last year) but will clean again. Also will clean burners as best as possible and the put the rollout switch in.

I was thinking of cleaning the heat exchanger also but it’s a bigger project unless I’m missing something. Access to heat exchanger is a challenge I would imagine.

Aquastat help

Comments

Categories