Melt Down Kills My Verti Stoker Control. Need Some Input

KLook · Post by **KLook** » Thu. Feb. 16, 2012 6:04 pm

An automag failed on the return line to my VF 3000 and ended up melting the pex line for the domestic hot water in addition to blowing off. Lets just say there was water everywhere. The only thing that I could not fix was the stoker control. It would appear to not like being submerged. I have done a search and looked at the Coaltrol, but I don't think it is what I want with a boiler. Has anyone built a simple control for this application? I can easily use a DPDT cube relay to control the stoker motor and combustion fan, but I need some kind of adjustable timer unit to handle the idle time. Any ideas would be greatly appreciated.

Kevin

KLook · Post by **KLook** » Thu. Feb. 16, 2012 6:24 pm

Would someone like to verify that 2 of these(
**Broken Link(s) Removed**) would do the job? I think they can control each other in a loop through the NC/NO switches and perform much like the control I have.

Kevin

WNY · Post by **WNY** » Thu. Feb. 16, 2012 6:52 pm

For idle, you can use a standard INTERMATIC Repeat cycle timers, that's what the Keystokers use. I think they are 30 min timers with 4-6 pins every 10 mins. or whatever is needed.

did you let it dry out good, maybe put it in a bowl of rice, it will suck the moisture out.

like this
http://www.amazon.com/Intermatic-C8835-30-Minute- ... B000GHLV5K

KLook · Post by **KLook** » Thu. Feb. 16, 2012 7:48 pm

Thanks for that, I wasn't sure they still made the mechanical ones! I think that is very reliable compared to some chinese printed circuit board and dashpots.

Kevin

Ziggy · Post by **Ziggy** » Fri. Feb. 17, 2012 8:05 am

I just overhauled and installed my new to me EFM 520 and in the process, looked real hard at the idle control process. I ended up using a timer made by Macromatic and am thrilled with it's flexibility, adjustability and performance. The one I chose is powered by 24v on the control side but switches two different 110v circuits. ( DPDT) I tapped into the existing oil boiler zone valve transformer and all is well. There are other models available but this is the one I used. Got it new on fleabay for 60.00.

Macromatic Time Delay Relay TR-63128 24v AC/DC input Programmable Time Range

Post by **Rob R.** » Fri. Feb. 17, 2012 8:19 am

An automag failed on the return line to my VF 3000 and ended up melting the pex line for the domestic hot water in addition to blowing off.

Melting the pex??? Can you explain how this happened? Sounds like something wasn't right with your control strategy. When you are replacing the controls, ask yourself what will shut down the stoker if the timer fails and stay's on...

That Macromatic repeat cycle relay looks like it would work fine, just get an enclosure and relay socket to go with it. The Intermatic timer listed above would also work fine.

KLook · Post by **KLook** » Fri. Feb. 17, 2012 4:29 pm

Yeah I can explain, I have a small bronze circ going 24/7 (Taco 003 I think) to take hot water off the top and return it to the bottom to even out the temps in the boiler. I have found it stratifies somewhat and the sensor is on the top naturally. It would not turn on until every bit of hot water was gone, so I made sure it is full of hot water. At any rate, this 3/4 copper return line was about 1 inch from the cold water supply to the domestic coil. It melted from both sides probably as the coil was full of exceedingly hot water also. It was so hot I had to tighten up the metal crimp rings on the pex tubing on both sides of the coil.

It would appear now that the malfunction was not the valve but the cube relay that controlled its operation. I can hear LSFarm now! Damn Rube Goldberg device using switches and relays that go bad!

I made a bunch of changes while it was drained down and I am going to add a backup plan. Still working on that. Probably include a Honeywell aquastat as I have not been happy with the Johnson controls.
Thanks for the suggestions, I'll surf fleabay and pic up something to play with.

kevin