I think my outdoor reset unit crapped out - looking for replacement

Not sure if this is the right forum or not - there's been discussion on this subject here in the past.

I don't think my Argo DPM-2 outdoor reset unit is working right anymore. I've checked the sensors' resistance values and they check out. There isn't much mfr. info out there on the unit. It was reasonable, seemed to work in the past, and plugged right into the Argo main controller.

The names mentioned on this forum include:
Tekmar 260
Intellicon HW+
Intellidyne
honeywell Aquatrol aq475

The heater is a Burnham V8 hot water boiler.

Would anyone have any suggestions? Maybe a heating forum?

Thanks.

VF

Thanks, I'll try them.

I am leaning towards the Tekmar 256.
I've seen it for $152
http://www.tekmarcontrols.com/prod/256.shtml

Thanks. I'm leaning towards an outdoor reset that lowers the max temp might save more energy.
My problem is integrating domestic hot water with priority.

That additional sensor is just for a tankless water heater which is a part of the boiler.
I have an indirect heater, which acts as it's own zone.
My existing controler, an Argo ARM-4P, has a domestic hot water priority feature in which other zones are denied heat even if the thermostats call for it, and the water circulating through the dhw tank is the maximum the boiler aquastat will allow. This priority means that the hot water will heat up faster (and it does!).
The problem is, the Tekmar 256 costs $150, but it's not exactly clear to me how priority is incorporated. The 260 model, however, incorporates dhw priority in the unit itself (along with other features).. alas it is ~$350. My price point is more in the $150 range.

I have the same unit. It really makes a lot of hot water, and I think the priority setting helps.

I ordered a Tekmar 256. I found a diagram of how to connect it to a similar Argo controller that I have as well.
http://www.tekmarcontrols.com/prod/256.shtml

Thanks. I'm wondering if the boiler might be "short cycling" 'cause it's really just heating the second floor. Not sure what "short" really is though. The Tekmar 256 has automatic differential that might help. It might not be as full featured as the other Tekmar units but it appears to be customizable to a good degree, has a lot of output info, and good documentation. Maybe an economizer as mentioned above would be better, but I do like the fact that this unit can be tweaked. I'll post pictures when I install it. Any operational info would be purely subjective (not that I'm not running up and down the stairs now checking stuff )