Fault codes are used on the Honeywell RM7800 series of boiler burner flame safeguard controls. These codes help the service technician identify problems that occur with the relay or the components that are wired to the relay.
These fault codes are sent to the S7800 display as so known as the KDM (keyboard display module) that can be mounted on the main RM7800 relay or remotely. The S7800 display will show operation and fault information along with other features
Over the years Stromquist and Company has been selling Honeywell controls and explaining these numeric fault codes to various clients. As luck would have it the other day I received a phone call from a client asking about a fault code that was showing up on his S7800 display. I searched the fault code references I had from Honeywell and could not locate the fault code the client was reading off the display to me. His fault code was 33Z. I have, in all my time working with clients, never saw or heard of a fault code ending with a letter value.
After several telephone calls to find an answer/solution to this problem I finally got an answer. It seems I forgot to ask one small detail about the client’s system.
When working with a RM7800 system and you get a bazaar fault code ask the client this question “Is there an S7830 Expanded Annunciator installed”. If there is a S7830 installed you need to look at the expanded fault code lists for the S7830 and there you will find the fault code number and in some cases this fault code number is followed by a letter giving you the proper diagnostic information.
I don’t know about you but this “ole dog” learned a new trick hopefully you can add this one to your bag of tricks.
More Boiler Burner Information:
http://www.controltrends.org/2011/09/rebuilt-flame-safeguard-controls-penny-wise-pound-foolish/
http://www.controltrends.org/2010/07/2061/
About Bill
Great info…I have run into problems with the Honeywell fault codes at times (I am new to boiler tech work) and this explains alot
Don’t feel bashful to ask questions about fault codes we are here to help and learn ourselves
Check out these other helpful how to’s….
heat exchangers….http://www.controltrends.org/category/burner-and-boiler/page/3/
honeywell controllinks…http://www.controltrends.org/2010/05/honeywell-controlinks-part-2/
Great post Bill. Very useful !!
Hi guys. I have a Honeywell. 7800 burner control. Every thing works I even see a piolit flame. But it keeps locking out on 28. I changed all parts with another unit and all controls work I changed out the cath rod too but no luck still locks out. Any help would be nice