120 volt Burner circuit on Gas boiler & Hydrolevel 3200

Aluvaboy

I have a Crown gas boiler feeding 3 zones in a 2600 square foot house in the North East. I was planning to replace the L8148A Honeywell Aquastat with a Hydrolevel Aquastat to achieve some fuel savings (?). I bought the Hydrolevel 3200 and was ready to install. But found that the burner circuit for Hydrolevel 3200 is 24 volts. My boiler with the L8148A has a 120 volt burner circuit. When I checked the Hydrolevel 3250 which has a 120 volt burner circuit, all the literature from the manufacturer says it is meant for an oil furnace. Is it true? I was also planning to call Hydrolevel tech support tomorrow.

Also on the Hydrolevel 3200 there are two terminals marked as I1 & I2. These are adjacent to the B1 and B2 Burner terminals. Their instruction/installation manual does not mention these terminals anywhere.

Can some experts guide me, please.

SuperTech

I've put a 24 volt transformer on the B1 and B2 terminals of digital aquastats such as that before, when I didn't have the 24 volt aquastat on the truck. It works well and gives the boiler the additional features that come with digital aquastat. I'm pretty sure Hydrolevel makes an aquastat for gas boilers, are you sure you got the right one? 

Aluvaboy

SuperTech said:

I've put a 24 volt transformer on the B1 and B2 terminals of digital aquastats such as that before, when I didn't have the 24 volt aquastat on the truck. It works well and gives the boiler the additional features that come with digital aquastat. I'm pretty sure Hydrolevel makes an aquastat for gas boilers, are you sure you got the right one? 

Hydrolevel 3200 is featured as the one for "gas boilers". This is advertised by the manufacturer. It only has the 24 volt burner circuit and 120 volt circulator circuit. I did not check out my boiler close enough before I ordered the 3200. Only when I was ready to install, I found that my boiler with the Honeywell L8148A works on 120 volt burner circuit. On further research, I found that Hydrolevel 3250 do have a 120 volt burner circuit. But it is advertised by the manufacturer for use on oil fired boilers. So my question really is- can I put the 3250 into my gas boiler. Is there a safety issue installing this. All the specs other than the voltage on the burner terminals seem identical between the two.

SuperTech

I would normally use a Hydrolevel 3150 or 3250 for replacement of a L8148A. The 3200 is a replacement for the L8148E or L8148J. I don't see any problems with using an aquastat for oil boilers on your boiler, but its kinda odd that a gas boiler has a 120 volt aquastat. What model boiler is it? Was it originally oil fired and converted to gas? Pictures would help.

Aluvaboy

SuperTech said:

I would normally use a Hydrolevel 3150 or 3250 for replacement of a L8148A. The 3200 is a replacement for the L8148E or L8148J. I don't see any problems with using an aquastat for oil boilers on your boiler, but its kinda odd that a gas boiler has a 120 volt aquastat. What model boiler is it? Was it originally oil fired and converted to gas? Pictures would help.

The Crown boiler I have is fitted with a draft inducer which is powered by a 120 volt/0.8 amps motor. The gas valve is in fact 24 volts honeywell. There is a step down transformer that has its primary connected to the 120 volt burner terminals in the Honeywell Aquastat L8148A which in turns power the 24 volt gas valve. See the circuit diagram below.

Even if switching to the Hydrolevel 3250, I will still have to retain the step down transformer for the power to the gas valve and related circuits. Correct?

SuperTech

Oh, OK. Can you just take the transformer off the L8148A and use it on the Hydrolevel 3200? That's would work fine, it's like what I mentioned in my first post when I mentioned how I used digital aquastats when I didn't have a 24 volt one. That would work perfectly. 

HVACNUT

SuperTech said:

Oh, OK. Can you just take the transformer off the L8148A and use it on the Hydrolevel 3200? That's would work fine, it's like what I mentioned in my first post when I mentioned how I used digital aquastats when I didn't have a 24 volt one. That would work perfectly. 

The 3200 is already 24v at B1,B2 so he can't use the transformer. 
The best bet would be to get the 3250 Plus and reuse the transformer. The inducer gets powered 120v at B1 so there's really no other way. 
Don't let the "oil" part fool you. It's a direct replacement for the L8148A. I have to admit, that wiring is a little atypical for a residential gas boiler. 

BTW, the "I" terminals on the 3200 are if you have an indirect water heater. Do you? The 3250 Plus has specific wiring for an indirect so it can bypass the economy settings. 

Aluvaboy

Thanks. So I will order the Hydrolevel 3250plus and rewire the transformer to feed from the B1 B2 terminals. I don't have an indirect water heater. I have a Rheem 50 gallon stand alone domestic water heater. I was worried about the "oil" part for the 3250.

MikeAmann

Now you have it. Usually OIL is 120v and GAS is 24v. In your case, ignore the word OIL and match the voltage. That would be the 3250+ for your situation.

Aluvaboy

MikeAmann said:

Now you have it. Usually OIL is 120v and GAS is 24v. In your case, ignore the word OIL and match the voltage. That would be the 3250+ for your situation.

Thanks. I will take that route. Ordering the 3250 plus now. Should receive it by Wednesday.

SuperTech

Aluvaboy said:

Now you have it. Usually OIL is 120v and GAS is 24v. In your case, ignore the word OIL and match the voltage. That would be the 3250+ for your situation.

Thanks. I will take that route. Ordering the 3250 plus now. Should receive it by Wednesday.

Did you order the aquastat well that goes with it? They call it the Electrowell, the 3250 plus has the built-in low water cutoff function, but it requires you to drain the boiler and replace the aquastats immersion well.

Aluvaboy

Yes I did. I ordered the 3/4 inch standard length electrowell. Should receive it tomorrow along with the 3250. I am also planning to drain the boiler to install two ball valves before and after the circulator. Will replace the aquastat well at this time.

While on this subject, I have yet another question. I am mounting the 3250 on the wall away from the Aquastat well. The reason is to have better access to the unit and to see the display at eye level. Since I have my domestic hot water boiler adjacent to the Crown boiler, there is not much room around the boiler and you have to squeeze yourself to get near the current location. So I ordered the 10' long sensor wire and the wall mounting bracket for the 3250. But it is still slightly short (about 3 feet). Can I splice the sensor wire to make it longer? It appears to be a four conductor thermostat wire. They do sell a 20' long sensor wire. But it is on back order.

MikeAmann

I don't know what you have for a circulator, but if a TACO, there is a ball valve & flange kit made just for that. Choose your size: https://www.supplyhouse.com/Taco-Bronze-Shut-Off-Freedom-Flanges-321000
Here it is installed on mine:


The sensor wires are just regular light gauge wires. Yes, you can extend them.

Aluvaboy

Thanks Mike. I have only one Taco circulator. That is the exact valves I ordered from Supply House. Hopefully the old brass couplings connected to the flanges in the current set-up will come out easily without much of a struggle!

And I am planning to extend the sensor wires to make it longer. I will post pictures after it is all complete.