Carlin 60200 vs. 70200

Tremain

This is my first time on this site and I'm a happy home-owner.
I have a Weil-McLain WGO boiler with a Carlin EZPro burner. The Primary is a Carlin 60200, still under warranty. It has developed a problem causing the boiler not to fire. The amber light flashes about once a second. The Weil-McLain tech advised me to slap the side of the primary (quite amusing) and this does, in fact, work. When I do this the boiler goes through its purge cycle and then fires.
So I suspect that this is a known issue and I'm wondering if anyone else has experienced this. It seems like it might be a cold soldered joint inside the primary and I plan on replacing it. Here's my main question:
I have a 70200 primary, which Carlin says is a compatible replacement. What are the pros and cons of using this instead of the 60200?

Jamie Hall

Do replace it. I have no thoughts on the merits of the two controls -- but what you describe could be a cold solder joint -- or a sticking relay. The former is not so bad. The latter could stick closed (instead of open) someday with very interesting (and undesirable) results.

EdTheHeaterMan

70200 control has a digital display screen that will walk you thru the setup after you properly wire the control. there are several diagnostic screens that will assist in troubleshooting other problems and show a history of the number of cycles since the last error code or other event like "x number of cycles since last recycle"

I have found this very helpful on nuisance calls involving intermittent failure that does not present when the service tech is on the job, but fails the next day after you have paid for a service call and nothing was able to be found.

on one occasion we found a faulty ignition transformer because the history showed "low voltage ignition circuit 8 cycles ago" but "normal voltage ignition circuit" on all the other cycles

The ignition transformer was working fine when I was there one day and was working fine when I returned the next day.

You must take care to properly wire the control. both the red (limit) and the black (power) wires must have voltage applied to the control at the same time for the control to start the cycle. if you don't have a separate power wire then put both the red and black terminals (wires) from the 70200 control to the wire coming from the limit. this makes programing the control difficult if the boiler or furnace goes off by the limit. since the power wire also looses power with this wiring configuration.

If there is no separate hot and it is easy to add a red wire from the 70200 control to limit or aquastat relay that is always hot. then there are more programing options available to you. Post purge, with a clean cut pump or delay oil valve, helps to keep the end cone carbon free after shut down. so much more capability and can be dumbed down to fit what is already there!

Look at the wiring diagram and if it does not do what you want, send me picks of the wiring you have and we can discuss it!

Tremain

Thanks Jamie and Ed for your quick responses. I had not thought about the possibility of a relay sticking shut, Jamie, and yes - ouch !
And thanks Ed for a very detailed response, which I'm digesting. The boiler will be serviced in about two weeks time so I'll let everyone know how it worked out.
Incidentally I haven't seen any internal wiring diagrams for the 60200. Does anyone know what's in there?

STEVEusaPA

Tremain said:

...
Incidentally I haven't seen any internal wiring diagrams for the 60200. Does anyone know what's in there?

Honestly nothing that would help you, or that you could (should) try to fix.
Just have the tech put the ProMaxx on. More features & diagnostics.
I honestly wouldn’t wait 2 weeks, unless you’re not using it. It’s THE main safety control, and it is damaged. So I wouldn’t trust it to shut off if an unsafe condition occurs.