Ultra O/D Reset Question

Mark Adams

Maybe someone knows this. The W-M Ultra control addendum shows that the reset curve only resets between the warm WX shutdown and 32F. Lower outdoor temps than 32F cause the boiler to make the design supply. Tekmar and others reset the boiler temp all the way from the outdoor start to the design supply.

My system is a mixture of radiant floor and fin tube fed by an Ultra 80LP. Is the only way around this to manually set the design temp when the outdoor temp is less than 32F? (it'll be <32F until March here near Buffalo, NY :-) The radiant is handled by a Taco RMB.

Thanks,
Mark

Clarence, NY

Uni R

Ultra Reset

The parameter is adjustable from 50F down to -4F. I think someone here said it may have a default of 32F because Weil asked for it to be zero and they were talking fahrenheit and the supplier took that to mean 0C/32F.

Empire_2

Ultra

The Tekmar control gives you a wider control on the temp curve and boiler operation. I have notice this as well on my first Ultra, but that is all they wish that control to do I thimk. They figure after 32* the boiler should fire at design setting. I will have to look into if the Tekmar can take the existing sensors place. Mike T

Mark Adams

Solved

Well, I solved my own question. The boiler control interface kit manual shows how to adjust many more parameters. This pdf doc is on the W-M site. The reset curve can be customized any way you like. Very nice.

L8R,
Mark

bob_34

i had the same problem and also found the directions for design temperature curves under 32 dgrees on the web site. this boiler has been out several years and still that info is not with the boiler for the installer to set. go figure.