I have a partial answer. Will find out the rest tomorrow.

There are different relays you can use but you are right the boiler should turn off and on from both relays. The relay
has to have a double pole, double throw switch that can start the pump and the boiler. this is a very simple think for them to do so stay after them to get it right. Your wiring diagram
should show the contacts in the relay. later paulbm

http://forum.doityourself.com/archive/index.php/t-386091.html

Check out that link for adding a Taco relay to your current aquastat and also type L7248A into Google for more answers. The L7224U might also work.

All electrical work must be done by a qualified electrician.

You can use an 832 or an 845 as the manufacturer suggests. On the 832 and 845 you would derive power from the same circuit, for safety, that the boiler is hooked to. Voltage would be taken from any L1 terminal or any black, power source wire for the boiler.

That power would be hooked to L1 of either relay.

If using the 832 the black wire from the burner would go under terminal 3 and the black wire from the circulator would go under terminal 4 or vice versa.

If using the 845 the black wire from the burner would be cut and one end goes under terminal 3 and the other end goes under terminal 4. The circulator black wires would then go under terminal 5 and 6. Or vice versa.

Look up the brochure under Honeywell's Tradeline series for R845A to see the schematics.

The service tech was back again today to fix the system. I worked late and wasn't here. He's added Another relay to the system (4 now in all including the one in the aquastat) and did remove the jumper across the 2 thermostat terminals in the aquastat, but it is still HOT in here! He has something jumped back into the aquastat from the new relay he added that I haven't figured out yet. The thermostats are set to 71 and with the temp at 79 in here I went down and shut of the power switch again....without killing the main power the burners keep lighting up even though the thermostats are satisfied. Am I correct in assuming that the honeywell L8148e does not itself contain a low limit controller, but that it has the provisions to have one added to it? (the L6006 or simaliar?). This aquastat has no controller added to it. The burners on this boiler should not fire unless a there is a call for heat from the thermostats, right? In a nutshell, shouldn't I be able to control the boiler completley from 2 indepentent thermostats, with 2 different circulating pumps in 2 seperate zones using the Honeywell L8148E aquastat and a Honeywell R845A relay? Where each thermostat will call for the boiler to fire if needed? And the burners NOT to Fire unless the thermostats call for it?

Puote: Am I correct in assuming that the honeywell L8148e does not itself contain a low limit controller, but that it has the provisions to have one added to it? (the L6006 or simaliar?). This aquastat has no controller added to it. The burners on this boiler should not fire unless a there is a call for heat from the thermostats, right? In a nutshell, shouldn't I be able to control the boiler completley from 2 indepentent thermostats, with 2 different circulating pumps in 2 seperate zones using the Honeywell L8148E aquastat and a Honeywell R845A relay? Where each thermostat will call for the boiler to fire if needed? And the burners NOT to Fire unless the thermostats call for it?

The 8148 is a cold start, meaning the burner and circulator come on when the thermostat calls for it. Otherwise, it doesn't maintain any heat. You don't need provisions added to it. If you wanted to maintain heat, you'd use an 8124A, but your boiler is probably small and has no coil, so you don't use one.

A thermostat controls the boiler, like you said.

Has the heat anticipator been correctly set on your thermostat? If using a T87F tstat, the anticipator on the newer L7248C calls for .1, the lowest setting.

Well the relays the service tech set up are close to being right....when each zone thermostat calls for heat, the boiler burners fire if needed and the corresponding circulating pump kicks on. the only glitch still in the system is that when the fist zone thermostat calls for heat, BOTH zone circulating pumps energize. I think I'm just going to buy the 845 relay and install it myself as per the schematics in the manual. Both circulating pumps energizing when the first zone calls for heat isn't really an issue at this point because the second zone has a much higher need for heat due to it being in a part of the house that has much older single pane windows...and a lot of them! The excess heat in the first zone appears to be from a "ghosting" effect when the second zone's circulating pump is energized. Hopefully adding flow check valves in the system will correct the problem....See the posting "Boiler Circulating Pump Zone Question" for further info. Thanks again for the input here!

I didn't notice that the two posts were related and I was just thinking along the lines of a relay/electrical issue. Yes, if you have no flow control valve, you'll have heat by gravity or uncontrolled circulation.

If both circulators come on when one tstat calls for heat, there is still a wiring problem if the zones are supposedly separated. This shouldn't happen and I believe the properly installed relay, either the existing 832 or the alternative 845 will solve the problem.

This valve does the same thing, but has a knob at the top to bypass the check valve for gravity heat. I'd say it's the more common one to use.

Here is a link that might be useful: Taco flow control valve

Any update on this issue?

The update is that there has been 2 problems with the system. The improper wiring of the relays by the service tech, and the ghosting effect in the first zone caused by lack of check valves in the system. The system was never set up properly from when the addition was put on the house. The second zone thermostat was wired to a relay that just energized the second zone circulating pump, it was never wired to call for the burners to fire, so the ghosting effect never showed itself. The water was never heated when the first zone didnt need it. When the boiler was recently replaced I asked the service tech to make sure that the second zone thermostat would call for the burners to fire when needed. He finally got the wireing somewhat close and now I am experienceing the unwanted circulation of hot water in the first zone. I am ordering the check valves I need online and installing them myself. I am also looking for a schematic to hook the existing thermostats, pumps and relays (L8148E & r845a) up correctly. I'll keep ya posted on the progress. If you have a url to this specific schematic application that would be great! Thanks again. Bill

The 8148E may or may not have ZC and ZR terminals. The new style 7248U does.

If you have ZC and ZR, you can wire to the 845A via the aquastat. If you don't have ZC and ZR, you have to take a separate 120V wire to the 845. Didn't I answer this on another post?

My 8148e does not have the ZC and Zr terminals, but jumping the 120v into the other relay is no issue. I did make a mistake in my last post, I have an existing 832 relay currently in the system, not the 845. I went to the link you had in a previous post but it did not relate to my particular aquastat and relay. You did post some instructions on hooking up the 832 but what I got out of it was you said to hook the burner up to terminal 3 and the circulator up to terminal 4 or vise versa.....aren't both of these terminals switched 120v? wouldn't I be sending 120v to a 24v gas valve or am I missing something? I'm no pro at this so thats why I am asking....I'm just trying to get this thing to work right for the first time ever. I've had an "expert" here a number of times and its still not right. I've been hoping to be lucky enough to find a clear schematic on hookig this exsiting aquastat to this existing relay correctly to run the two zones properly.

See figure 8 of the brochure. You'll have to use the 845. An RA89A can also be used to switch low voltage.

Here is a link that might be useful: R845A

I finally got the system wired and working right. I wired the aquastat as per manufacturers instructions to run the first zone. I used the 832 relay hooked to the second zone thermostat to run the second zone circulating pump. There as also an aux. switch in the 832 so I pulled low voltage out of the aquastat, through the 832's aux. and back to the "B" in the aquastat to fire the burners.... works perfectly. Thank you for your help baymee.

My pleasure, fellow wood boiler operator!

I am my churches head matiance person for the heating and cooling systems we have a boiler and what this mechanic tells you is false your relays should be wired so the when one pump is running and the water is not hot enough that the flame lights and our boiler system is fairly old so the technology needed for you to do this is out there so the mechanic is false and probably just want you to spend more money hope this helps ps our pumps use honeywell relays

Just hook the thermostat wires to the primary ignition

Are they interchangeable