L8124A Converting from Oil Domestic Hot water and Oil Heat to Electric Water Heater and Oil Heat

bossjj98

L8124A Aquastats on both boilers, the domestic hot water lines have been capped. I converted from oil for heat and hot water to electric water heater and oil burner for heat.

Looking for advice on what to do with the aquastats. I saw some posts about adjusting the settings or moving wires around so that the boiler will be a cold start only, or winter only boiler?

Right now the boilers still come on without a call for heat.

Should I let this be all spring and summer even when there is no need for heat?

Should I just kill the power to both of them? I’m worried that would do more harm than just letting them run during the year.

Someone should know the best way around this!

Thanks for your help!

bossjj98

Both Aquastats pictured

SuperTech

Simplest thing to do, just turn the low limit all the way down or switch the boiler off when not using heat. 

I wouldn't leave the unused pipes from the hot water coils capped. It's best to leave them open.

bossjj98

bossjj98

SuperTech said:

Simplest thing to do, just turn the low limit all the way down or switch the boiler off when not using heat. 

I wouldn't leave the unused pipes from the hot water coils capped. It's best to leave them open.

I attached photos of where we capped the connections, I was told water could still come out of them so capping is ideal, however that was my plumbers advice.

Also I read that it’s good to let the boiler run every so often to avoid it from having issues in the winter with starting back up, moisture, or something else.

SuperTech

I always leave those coil pipes un capped. I don't want any remaining water in the coil possibly boiling and turning into steam and building pressure. I've never seen anyone cap them. 

It's good to run the circulator every once in a while if the boiler isn't operating for heat or hot water. Modern digital aquastats do this for you.  

bossjj98

Is there a new digital Aquastat that you recommend I get for this purpose? Good idea, I’ll try to get the caps off. I was told the remaining water would boil away.

HVACNUT

bossjj98 said:

I was told the remaining water would boil away.

And go where? 

LRCCBJ

bossjj98 said:

Is there a new digital Aquastat that you recommend I get for this purpose? Good idea, I’ll try to get the caps off. I was told the remaining water would boil away.

You'd be very pleased if you replaced the L8124 with the L7224. Digital display of all parameters that you require. You can turn off the LL if you choose. You can swap them in about 60 minutes if you're fast!

EdTheHeaterMan

LRCCBJ said:

bossjj98 said:

Is there a new digital Aquastat that you recommend I get for this purpose? Good idea, I’ll try to get the caps off. I was told the remaining water would boil away.

You'd be very pleased if you replaced the L8124 with the L7224. Digital display of all parameters that you require. You can turn off the LL if you choose. You can swap them in about 60 minutes if you're fast!

Easy low cost fix here


You can complete this in less than 6 minutes. If your good in under 60 seconds.

SuperTech

bossjj98 said:

Is there a new digital Aquastat that you recommend I get for this purpose? Good idea, I’ll try to get the caps off. I was told the remaining water would boil away.

I also like the L7224U aquastat.  It has a pump cycling feature that will exercise the circulator pump once in a while if it hasn't been been running. You can easily set it up with the low limit off now that you don't need the tankless coil.  The Hydrolevel 3250 plus is another good option. 

bossjj98

EdTheHeaterMan said:

Is there a new digital Aquastat that you recommend I get for this purpose? Good idea, I’ll try to get the caps off. I was told the remaining water would boil away.

You'd be very pleased if you replaced the L8124 with the L7224. Digital display of all parameters that you require. You can turn off the LL if you choose. You can swap them in about 60 minutes if you're fast!

Easy low cost fix here You can complete this in less than 6 minutes. If you’re good in under 60 seconds.

Would this make it a cold start boiler?

SuperTech

bossjj98 said:

EdTheHeaterMan said:

Is there a new digital Aquastat that you recommend I get for this purpose? Good idea, I’ll try to get the caps off. I was told the remaining water would boil away.

You'd be very pleased if you replaced the L8124 with the L7224. Digital display of all parameters that you require. You can turn off the LL if you choose. You can swap them in about 60 minutes if you're fast!

Easy low cost fix here You can complete this in less than 6 minutes. If you’re good in under 60 seconds.

Would this make it a cold start boiler?

Yes it would. 

bossjj98

SuperTech said:

bossjj98 said:

EdTheHeaterMan said:

Is there a new digital Aquastat that you recommend I get for this purpose? Good idea, I’ll try to get the caps off. I was told the remaining water would boil away.

You'd be very pleased if you replaced the L8124 with the L7224. Digital display of all parameters that you require. You can turn off the LL if you choose. You can swap them in about 60 minutes if you're fast!

Easy low cost fix here You can complete this in less than 6 minutes. If you’re good in under 60 seconds.

Would this make it a cold start boiler?

Yes it would. 

It would only turn on in the winter? Do you see any issues with that?

EdTheHeaterMan

bossjj98 said:

EdTheHeaterMan said:

LRCCBJ said:

bossjj98 said:

Is there a new digital Aquastat that you recommend I get for this purpose? Good idea, I’ll try to get the caps off. I was told the remaining water would boil away.

You'd be very pleased if you replaced the L8124 with the L7224. Digital display of all parameters that you require. You can turn off the LL if you choose. You can swap them in about 60 minutes if you're fast!

Easy low cost fix here


You can complete this in less than 6 minutes. If you’re good in under 60 seconds.

Would this make it a cold start boiler?

YES, however the DHW priority feature of the control is still connected, which means that the circulator pump will not operate if the boiler temperature is below the LO setting. That is why I recommend setting the LO as low as you can... 110°F

There is another step that will solve that, however I like the 110° minimum temperature for circulator operation. That minimizes the flue gas condensation a bit if you find that you need it, because the soot is wet during the next tune up. You just need to increase the LO setting to 125° and the Flue Gas condensation will go away sooner in the cycle. (this all depends on the radiators you have. Cast iron will have more of a chance of Flue Gas Condensation... Copper Tube Baseboard not so much)

If you find that you don't have the flue gas condensation problem, and can operate as a cold start boiler then you just remove the R and W wires from the LO side of the control and wire nut them together. Now you have the equivalent of the L8148 control.

If you want to see the internal wiring of the L8124 and the L8148 you can look here.https://forum.heatinghelp.com/discussion/comment/1798670#Comment_1798670?