Trooper's Circulator Post Purge "Mod"

[DaveC72]

Thanks Trooper, I ordered one (the 24v ac version).

Good find on these controls Rockledge, I could see ppl using them for all sorts of things (how about monitoring and adjusting the temp of an outdoor wood boiler from inside the house !)

Sry on the thread hijack.. I should have posted a new one about this.. got too excited once I looked into this control, and forgot my netiquette.

[Rockledge]

Good find on these controls Rockledge, I could see ppl using them for all sorts of things (how about monitoring and adjusting the temp of an outdoor wood boiler from inside the house...

When I read through the Product Reviews for the unit at the PexSupply site, I was pleasantly surprised at how versatile the Ranco control actually is. I'm especially intrigued by all the home brewers who give it a big thumbs up.

[PeterNH]

Back in the day, when i was in the restaurant business.
A Ranco control on a refrigerator was the "cats meow," and then some. Accurate, with adjustable differentials and bullet proof.
The adjustable differential would help in tweaking a refer to keep it from frosting up.
Any time a junk stock t'stat on a free standing refigerator would crap out, We'd pony up the money and have a Ranco installed.
Case closed. I think they last a life time. There are some i know of running over 40 years and still going. Of course these were the old mechanical style.
I expect the same quality from the new electonic ones.

Peter

[NJ Trooper]

By the way, that same control is available in several 'flavors':

120/240 or 24 VAC power,

with a 0-10VDC control voltage output proportional to temp (very wide range!)

there is a 2 stage output available also... (I believe the ratings on the two relays are different!)

and also a NEMA 4 enclosure.

ETC Supply

[TBurr]

So when all's said and done, does the Ranco do a good job at post purging individual zones and is it a worthwhile investment for a multi zone hot water system?

[DaveC72]

It seemed like for nearly every config except a single-zone , the control logic is complex.
I thought about dumping heat to one zone (our foyer), but another zone might call for heat during the dump.. ok, so we make sure the t-stat supply line is cut during dump.. but then as soon as the 'cooling mode' of the controller is hit, the t-stats would reenergize and the boiler would ramp back up to high temps.. causing the controller to re-engage to dump that heat, etc.

I think the dump-room would start getting pretty hot.

Im just gonna use my Ranco to widen the high-low range on my aquastat (heck of a lot cheaper and easier than swapping out the aquastat).

[rbeck]

I am in and out of this conversation but maybe we need a different approach. How's bout this thought when using zone valves with a multi-zone panel. A dump zone into the largest zone or the one that calls the most with a zone valve, aquastat, small relay off the end switch of the multi-zone relay and a pipe from supply to the most used zone. Most zone valve panels will have the contacts needed.
When a zone calls a relay with NC contacts will be activated from the zone panel, which opens the relay. When the call for heat ends, the strap on aquastat is already made, which works like a thermostat, opening a zone valve. The end switch on the zone valve will activate another relay to run the pump. When the temp drops enough the aquastat opens and shuts it all down. The price of two relays which can be purchased for less than $20, a zone valve, an aquastat, a bit of piping and some wire. If another zone calls it opens the relay for the zone valve and the dump zone closes.
The same concept could probably be used with multili-pump relay
If there is no zone panel you could just add the relay on the end switches from all the heating zones to a relay. This time a DPDT switch will make for the alternate aquastat, breaks T-T on the boiler and energizes another relay for the pump. There are inexpensive relays which can be used for this, look up RIB relays. They mount on bknockoutstys and have NEMA approvenclosuresers for less than $15 usually.
Either way if we get another call this will de-energize and shut down the dump zone as the relay kills power to the dump zone valve or pump.
Matbe we could apply the same configuration to en existing zone valve system with no panel?. Much more thought. Use a relay to open a dump zone, kill the call for the end switch, energize the TT on the dump zone valve and have the aquastat operate A DPDT relay pump? Two DPDT relays would do it. The one would be operated by the end switch on the zone valves the second operated by the aqustat.
I will work on a diagram to show what I am thinking.

[PeterNH]

Second thought couldn't we apply the same configuration to en existing zone valve system with no panel?.

Hello Rbeck, Dave, TBurr, Everyone,

No need to re-invent the wheel.
We have done this already.
NJT the "wiring Bishop" approved.
See here:
Post Purge with Zone Valves

Peter

[DaveC72]

This seemed to have spawned off another unconnected thread right ? I missed that one, but I assume we were looking for a way to evacuate the high heat in a boiler into a useable space somewhere in order to reduce stack/standby losses of a hot boiler ?
Dumping the heat into the structure somewhere, where you dont mind the heat delta ramping up and down is a decent approach, but wouldnt it actually be better to put it into storage somehow (like a superstore tank etc) ? When you dump it onto the structure, you raise the delta across the outside wall(s), increasing loss rate. A sealed storage unit would 'hold' the btu until needed, notwithstanding the thermal loss from the storage unit itself (and if you put that in a convenient space... coffee-table storage unit anyone ?).
My boiler radiates up into the drop ceiling between our floors, helping the upper floor keep warm to some extent.. but I would like to reduce the stack losses for sure someday..

[PeterNH]

Dumping the heat into the structure somewhere, where you dont mind the heat delta ramping up and down is a decent approach, but wouldnt it actually be better to put it into storage somehow (like a superstore tank etc) ? When you dump it onto the structure, you raise the delta across the outside wall(s), increasing loss rate. A sealed storage unit would 'hold' the btu until needed, notwithstanding the thermal loss from the storage unit itself (and if you put that in a convenient space... coffee-table storage unit anyone ?).

Hello Dave,
I think the best way to get the most heat out of the boiler is to find a large delta t between the boiler and the "purge dump."

If the water at the bottom of the indirect is cold then it would be a good place to put it.
If it has just gone thru a cycle and is hot and not much water has been used for many hours, then the first floor zone in my house would be the next best place.

I think you just try somethng and if it seem to cool off the boiler while going to good use, that's it. Otherwise, make a change and try a different zone.

Peter