HTP UFT-80 doesn't enter heat mode; Indirect DHW operates fine

PC7060

Hello all,

Currently dealing with a problem than began after a power outage.

HTP UFT-80 (series built after 1/1/2020) doesn't enter radiant heat mode. Boiler is reporting no error message and ODR value in display mode is reporting correct outdoor temp (38F). Indirect tank heating operation is working normal.

Control panel passes visual inspection; 1 led indicating green.

Shorted across the TT input to bypass T-stat; no change to boiler function or boiler display.

Display panel is displaying solid House symbol and radiators. Note the image show below is an outline but I believe the solid house is normal

Any suggestions?

Thanks

PC

mattmia2

How is the dhw controlled? Does it think it has a DHW call and is set for DHW priority? I thought the little radiator symbol was domestic heating and the house had something to do with odr.

mattmia2

Does it have a lwco installed?

mattmia2

mattmia2

you could connect like a 9v battery to the 0-10v in and see if that generates a heat call.

PC7060

https://forum.heatinghelp.com/discussion/comment/1848872#Comment_1848872

internal to the boiler but that would inhibit DHW call too

PC7060

Hi Matt,

DHW is controlled using the HTP internal control logic and sensor; that seems to behave well. No aquastat.

PC7060

Thanks for the tip, i'll give this a try

GroundUp

I recently came across a Ruud 140k combi (same control/display as the UFT) which was having a similar issue. DHW worked just fine but space heating wouldn't show a call after several years of service. I replaced the whole boiler per Ruud under warranty and had the same problem. It was found that the new boiler had a faulty control board so I had to take the old board out of the old boiler and put it into the new boiler but still had a problem, then in a last ditch effort I just bypassed the original 0-10V control and went straight from the zone controller to the stat terminals and the problem went away. I don't know enough about the 0-10V control to say what the problem was, but I know it disappeared after the 0-10V went bye bye. With that said, the radiator symbol would never show up for me until I deleted the 0-10V. Maybe tech support would be a good start here, though they sure weren't very helpful for me.

PC7060

https://forum.heatinghelp.com/discussion/comment/1848884#Comment_1848884

Thanks for information. I'll disconnect the ODR and set what happens.

I checked all the installer settings on the unit; all look good. Considering doing a system reset to default settings.

Shorting the TT line lights up the front panel LED but not fan, pump or ignition actions are started. No warm weather shutdown indication. Hoping @Ironman has some ideas. 😎

mattmia2

do you have 24vac out of the transformer?

PC7060

https://forum.heatinghelp.com/discussion/comment/1848904#Comment_1848904

yep. Also disconnected the ODR sensor per @GroundUp post and the boiled fired up on TT call for heat. Also got the flashing home symbol per IUOM. Hmmmmmm. 😶

reconnected ODR and boiler switch to 90F SWT based on outside temp of 61F.
I don’t believe this is permanent but will see at next heating cycle.

mattmia2

what is wwsd set at?

PC7060

https://forum.heatinghelp.com/discussion/comment/1848921#Comment_1848921

Matt, wwsd is set for 68f. Temperature outside was 40-65f range when testing. Also the wwsd icon didn’t display.

resetting the OdR modules seems to have cleared the issue. Maybe a firmware bug?

mattmia2

probably more like some eeprom got corrupted.

PC7060

Boilers is operating fine after disconnecting the ODR and reconnecting after short run in standard mode. 😊

Thanks @GroundUp and @mattmia2!

mattmia2

I think you figured it out yourself