HTP Elite

Alan (California Radiant) Forbes

I've been working on this boiler for a few days now. It's throwing F00 and F05 error codes (excessive temperature) and I've replaced the pump, ECO sensor and operating sensor and the problem persists.

The last time I was out there, I noticed that the pump stops before the DHW is satisfied; the boiler starts kettling and then errors out. Before the errors show up, the display shows "PUMP ON" and there is no power to the pump and no call for heat.

The pump is powered via the boiler, not via a separate pump control.

This is quite an anomaly. I'm thinking it needs a new circuit board. Has anyone had experience with this problem?

mattmia2

Could be worth looking at where the relay solders to the board to see if it wasn't quite soldered right at the factory and has worked loose over time.

Edit: Is there 120v to the board? If the transformer is external to the board like I think it is in the UFT once it lights it might continue to run happily without 120v to the board if a connection is bad somewhere.

Teemok

I haven't seen an elite do it but I've seen boards fail like that. I think you are on to it. Bad relay. Loose wire? There's no funny wiring between boiler and pump? In a pinch I've switched to an SR relay and tank stat and used the switch option DHW call instead of the sensor. Some customers will pay a lot for a temporary hot water solution now.

tim smith

sounds like board to me. Look at the solder joints on back of board where pins from relay go through. Find them loose sometimes. On other models, don't see many Elites around here.

Alan (California Radiant) Forbes

The board is similar to Munchkins, so it has an onboard transformer. 

Elites are few and far between here as well. This one is for an HOA. They have six buildings; each one has a different boiler. 

I’ve also queried HTP by email, but haven’t heard back. With new ownership and considering how many products and units they have out there, I’m not holding my breath. 

tim smith

you can figure which relay on board is for pump, follow the solder traces from pump terminals on board to where they terminate, that will be relay for it. Just a note. Kind of unusual if it only happens near end of a cycle?