TecMar 256 and Aquastat L8124E - Help

TerrS

I am looking to make my boiler more efficient and got recommendations to install either a tecmar 256 or a Beckett Aquasmart 7600A. BTW there is no DHW in this gas fired boiler, So I do understanding maybe changing out the aquastat L8124E might be the right answer so that it doesn't maintain a LOW boiler temperature. Given that, I see that the Tecmar recommends having a high limit safety, I am guessing because all electronics can fail and the boiler could go over-temp. So if I assume that, how does one wire the tecmar 256 to the L8124E? In reading the specs and I am far from totally understanding how either electronic controls really work.

My questions:
1. Is there a wiring diagram to support using the tecmar to the aquastat well bulb fitted?
2. Does the Tecmar also maintain a low boiler temp, or just dynamically change the high setting so as the house requires heat, 165 degree water might be good, or It might need the 185 degree to make sure there is enough radiant heat coming from my slant-fins?

Any other help would be appreciated?

STEVEusaPA

I would just install a HydroLevel 3200. It has the high limit, and circulator hold off.
Set it up for cold start (Low Limit Off). Change the well and get low water cut-off also.
And you can play around with the other options to help save a little more money running your boiler.

HVACNUT

What make and model boiler? Gas boilers didn't come with triple aquastats unless they had a tankless coil. And that was many moons ago. How old is it?
Or is it an oil boiler with a conversion burner?

MikeAmann

I agree with STEVEusaPA on the Hydrolevel, but I have to ask - is your LO limit still in play with your 8124E?
The LO limit should have already been disabled (since you don't have a tankless coil) and is as easy as disconnecting one wire from the white block in the aquastat. All other functions will still operate as intended.

Having said that, these old aquastats are now DUMB antiquated switches compared to the SMART programmable controllers that are available now.

TerrS

So it looks likes a newer L8124E, I just bought the house a few months ago, so not exactly sure why the L8124E was installed, since I have a separate water heater. The furnace looks around 25 years ago, based on what I read on the side of the DUNKIRK. What brought my attention to this was I noticed my furnace runs about 10 times an hr, but only 1 minute at a time, I guess to keep that low temp setting. on the plus side I guess, I do get heat in about 9 minutes, to my slant-fins and Kick Radiator. Not sure how long it would take heat water from 70-110 which is were the Low setting is set. So a trade off I guess.

So I tried removing the white wire beside the differential and the boiler will not fire, I also read to remove the blue wire off the white block, but haven't tried that yet. Also not sure I want to modify to much, but as a temporary fix I could try if someone knows?

Lastly, the Aquasmart 7610B, looks like my best solution from what I am reading, It is a direct well replacement type and has options to delay pump shutoff even after the thermostat is not calling for heat. That would probably give me another 5 min of residual boiler heat, since I see 185 degree water being left wasted.

I will look at the hydrostate 3200, any plus's or minus to either? but I do see the becketts heatmanager is also apart of the Aquasmart, Which might also help overall.

Thanks everyone!

MikeAmann

Post a pic of the aquastat and we can tell you which wire to disconnect to disable the LO Limit.

STEVEusaPA

MikeAmann said:

Post a pic of the aquastat and we can tell you which wire to disconnect to disable the LO Limit.

I don't recommend modifying a UL listed safety control. Just change it to a modern one.

MikeAmann

STEVEusaPA said:

MikeAmann said:

Post a pic of the aquastat and we can tell you which wire to disconnect to disable the LO Limit.

I don't recommend modifying a UL listed safety control. Just change it to a modern one.

Doing this is not an unapproved modification. The instructions are in the manual - put there by Honeywell.
Just because 99 out of 100 boiler techs never read the instructions..........

Suppose you have a boiler with a triple-acting aquastat (HI and LO limits) and the tankless coil fails. You decide to abandon the coil. Now you no longer need the boiler to keep the water warm for the tankless. That is why those instructions are there. Disabling the LO Limit is allowed.

These Honeywell aquastats are somewhat universal. Honeywell has no idea what geographic location and what configuration the control will be used. Have you ever configured one to be a cold start?
Is that an unapproved modification?

MikeAmann

Here is an example using my R8182D. This is right out of the Honeywell manual.
Notice what I highlighted in RED. And the triangle with the number 2 inside. This is how Honeywell tells you to wire this control as a cold start.

The next picture shows how Honeywell says to replace the white block aquastat in different models of R8182.




But I absolutely agree with you. The new modern controls can do way more and much easier than these outdated switches.

SuperTech

I would also go with the Hydrolevel aquastat. It does everything that the aquasmart does but it's more reliable. I see a lot of issues with the aquasmart with the low water cutoff built in.  

TerrS

Thanks for all the recommendations. My heating person installed the Aquasmart 7610B , last Friday and so far seems to be working great. He set circulator to have a 4min delay off and 2 minutes for on, to try and allow the water to heat in the boiler first. Lastly he set max temp to 185 degrees.

This boiler has no LWCO installed, not sure why, but no-one noticed it, and we didnt swap out the well when the aquasmart was installed.