Why are my wires on L8148L aquastate disconnected

mo8414

The wires going to the upper right corner are just taped up. It shows them connected to the board on the pictures of the new one. I have to replace this one so im wondering if I need to disconnect the new one or just leave it the way it comes. Ill post more pics when i get home if needed

New one

PeteA

you will need to take a couple of more photos of your boiler so everyone can see exactly what controls your boiler has that makes it turn on and off since it doesn't look like this is the main controller at this time.

mo8414

Here is another shot i found on my phone

HVACNUT

It looks like the transformer in the aquastat failed, so an external one was used.

You should be able to just remove the wires from the external transformer on both sides, but I wouldn't say for certain unless all wiring is checked.

mo8414

Ok thanks

mo8414

So the thermostat wires red and light green come in and connect to one lug on the external transformer.

Then thermostat wires white and blue connect to the other lug of the external transformer.

EEach Lug as a single wire that goes to the aquastate(light green and blue). One lug wire goes to Z(light green) in the aquastate. The other lug wire goes to TV.(blue)

So if I get rid of the external transformer do I just connect two of the thermostat wires to Z and two of them to TV since the new aquastate will have its intermal transformer connected?

109A_5

Do you have zone valves or thermostats that require 24 VAC power ?

I suspect someone determined the transformer in the aquastat was not robust enough to power the whole system so they ran the whole system from a electrically larger external transformer.

I would hook it up as it was, however cutting or disconnecting the 4 wires from the internal transformer may void the warranty.

Leaving the internal transformer connected may cause other system problems. The big picture needs to be understood to make good decisions.

Why are you changing the aquastat ?

EBEBRATT-Ed

Looks to me like you can just pull the two transformer wires off the pins on the board and leave all the wiring connected as is

109A_5

https://forum.heatinghelp.com/discussion/comment/1844665#Comment_1844665

Yeah hopefully the wires are terminated to a small push on connector and just not a strain relief and soldered to the board, can't really tell from the picture of the new one.

The ones I'm more familiar with the transformer is soldered directly to the circuit board.

mo8414

Ok, yea there are 2 zone valves. I'll just cut the wires in a way that they can be reconnected if need be if I can not just pull them off the board. Ill update tuesday when I get it. It kind of seems like it might be set up just to pull them off the pins otherwise why have it be a pin like that ya know. We will see.

mo8414

Also I'm changing the aquastat because its not giving the circulator 120v and it smells like something burned up. Its also been acting funny lately where it turns the burner on for about 3 seconds then shuts it down occasionally and clicking louder than normal.

HVACNUT

https://forum.heatinghelp.com/discussion/comment/1844685#Comment_1844685

The factory wiring has obviously been altered, so double check everything. Can you draw or show all control wiring so we can follow it? Adding a Rollout and Spill Switch wouldn't be a bad idea either.

mo8414

When I get some time ill try to see how all the wiring goes and probably draw it out. Its a giant ball of wiring mess up by the zone valves so it wouldn't hurt to sort that out anyway.

mo8414

I just got done tracing the wires. What a mess. This is the best I could draw it out. Blue on my diagram could also be seen as dark green its hard to say for sure.

EdTheHeaterMan

It appears that you have the L8148L control that is compatible with Millivolt and 24 volt gas valves. There is an on board 24VAC transform that is connected to Z and TV under the circuit board by way of those T1 and T2 pins. By reomvinf thoas pins the on board transformer may be disconnected. An external transformer can be connected by using the Tv and the Z terminals on the L8148L.

Since you are going to be replacing the control anyway, you may want to connect the zone valves to the external transformer and not use that transformer forthe replacement control. Look at the HydroStat 3200 Plus, because it is a better control with more features and it costs less, by over $100.00

Wire everything the same way except the Blue and Green wire from the zone valve aux transformer to the new control. (the same works on the more expensive control also L8148J also)

Your system is using the 24 VAC burner terminals B3 and B1 so that means you have a 24 V gas valve or ignition system.

109A_5

https://forum.heatinghelp.com/discussion/comment/1844685#Comment_1844685

OK, I suspect the solder joints that connect the relay to the circuit board are failing, common defect.

Your zone valve wiring is not quite the way I would do it, but it looks like it would work.

mo8414

Thanks for going over it. Its definitely not wired like the videos I have watched and I'm not familiar with it enough to know what order of operation it goes in but its been working so you much be right lol. I should be getting it today.

mo8414

Would this also work?

EdTheHeaterMan

i would always connect the R (load) from the transformer to the R on the thermostat. then connect the W from the thermostat to the motor on the Zone valve. This is a good habit to get into for future reference.Your diagram does not show the aux transformer connected properly. You need to use the Z on the L8148

I would also use the onboard transformer and not use the Aux (zone valve) transformer to power the control.

mo8414

So this is the setup It is right now. If I remove the blue wire going from transformer common to TV.

then Remove the green wire going from transformer load to Z and leave the aquastat transformer connected instead of disconnecting it like it is now, would this wiring configuration work? I would like to not have to disconnect the onboard aquastat transformer if I dont have to but I also don't wanna mess anything up.

EdTheHeaterMan

Here is your diagram with the correct wiring…..

make this a habit:

R on transformer to R on thermostat.

W on thermostat to Zone valve motor (black wire or yellow wire)

Other zone valve motor (black wire or yellow wire) to C on transformer.

That completes the thermostat to motor circuit.

If you always follow this method of wiring a zone valve, you will always be correct. If you have any other design from someone else, that you may or may not have a problem with your transformer loosing all the factory installed smoke.

The transformer factory takes great effort to install that smoke just right. If you make a mistake, then you may let the smoke out and then you will need to throw that transformer away and start overwith a new transformer.

The next thing you need to know is that electric is colorblind and does not know what color the wire is on the outside. So you can use a Green wire for the trip from R to R and a Brown wire on the trip from motor wire to C. I just think it is easier to use a Red color wire when making the trip from R to R. I'm Just funny that way!

mo8414

Thanks a lot I really appreciate it.

EdTheHeaterMan

Here is the digram from Honeywell for 5 zones. I have removed all the wires that you don't need and the first three zone valves so you can see your 2 zone system.

This is identical to your hand drawn diagram with my changes.

If you follow the transformer R to the thermostat R everything else will fall in place.

mo8414

Well I just got it all hooked up just like the diagram. My living room worked fine but my family room wasn't working at all so I triple checked the wiring. Then I decided to just connect the wires at the thermostat and I guess I also have a bad thermostat so I need to get one of those.

When the wires are tied togeather everything works as it should. So both zones are working now. I cant express how much I appreciate you helping me on this! I know it would have worked with my old wiring setup but I'd rather it be connected the correct way.

Just as I thought it ended up being the contactor that burned up, you could smell it. Thats also why I wasn't getting 120v at c1 and c2 because that pin burned up.

Thanks again

109A_5

That solder joint failure is quite common and actually can be repaired (actually improved) if there is nothing else wrong with the relay. Thanks for the picture.

mo8414

Yea no problem I figured you guys would wanna see it. Thats cool you could just repair it, makes sense that you could since its just soldered in.