Aquastat With Post-Burn Purge?

[quote="McGiever"

Ahhh...I like that, too! Gadgets that save money...awesome!

Any idea how much those run?[/quote]

US $21.95
http://www.ebay.com/itm/ICM-Controls-ICM254-ICM254B-Dual-ON- ... xyVLNTATjz[/quote]

Definitely NOT the way to get it done! It would take four of these and a mass wiring dilemma to make it happen.

He wanted a price, so I link one.
But, Thanks for saying how NOT to do it.

My own personal way of thinking of a solution to run his pump to move heat is to NOT use any timer application what so ever.

I would say to do it base on temperature of the pipe...break circuit after pipe temp is lowered to set-point.
Pipe temperature sensing switch wired in parallel to normal pump circuit...can't get much easier than that.

Hey...WOW!...5000 posts now.

McGiever wrote:He wanted a price, so I link one.
But, Thanks for saying how NOT to do it.

My own personal way of thinking of a solution to run his pump to move heat is to NOT use any timer application what so ever.

I would say to do it base on temperature of the pipe...break circuit after pipe temp is lowered to set-point.
Pipe temperature sensing switch wired in parallel to normal pump circuit...can't get much easier than that.

Hey...WOW!...5000 posts now.

Once again, it takes four of those and a mass wiring dilemma to do it that way. Read the first post again.

Okay, I did re-read.

Until the OP comes back asking some more I'll be still.
I would suspect there is some heavy PM'ing going on anyways.

McGiever wrote:I would suspect there is some heavy PM'ing going on anyways.

Not from me. I encourage all info to be on the main board...except for the extra special coal source info that I keep in my black book.

I like the idea of a simple 4006B aquastat wired to keep a circulator running until the loop temperature drops, but it would definitely take some trial and error to get it setup properly.

Honeywell makes a fancy zone control panel that includes some sort of post-purge feature. I will dig up the info later.

Thanks for all the replies! I was tied up yesterday at an appointment that went from 2hrs to 11hr onsite and an hour each way of travel. Skipped lunch, no drinks, etc. I was pretty hammered when I made it home, didn't get a chance to check in on the threads. No PM's, just beat, LOL.

The relays McGiever posted are the second best alternative. I had actually searched for just those, but without much luck. Yes, they would require me to run a second power bus to each zone I wanted to use them on, and then my expensive Taco SR504-EXP zone relay controller would not be doing its job.

I would be recreating it, as I cannot separate the TT from the power as it has its own relays internally. Now, if I didn't have one of those, it would be PERFECT for the zones, as I'd just use TT to trigger the relay (not sure about voltages, I'd have to find the particular model for 24vac coil and 120v load), use a 24vac transformer to power all the thermostats, and then to the pumps.

Not a bad design, just not sure I want to redesign and duplicate my controller. Now...maybe I can do it for our main living area zone, that wouldn't be too bad. Run a separate power line to the pump and let the power from the relay controller (going to the pump now) be the coil side of the relay, then I can play with just one zone and see if it is worth expanding.

The second problem is the running of the main circulator pump once TT has been satisfied. My Taco SR504-EXP takes all 4 zones' TT, does its work to power the appropriate zone, and passes a single "TT" to the boiler when any one or more zones are calling for heat.

If I'm going strictly time based post-fire purge, than I can do the same thing with the pump. Run a separate power line to the pump and use the current one to trigger the timed relay.

Again, quite a bit of redundant parts- which is why I was also asking about a Triple Aquastat with that feature. The Hydrostat 3250 is ALMOST the right answer...it has "pre-purge" but not "post purge". Perhaps because of the extra stuff needed to keep the individual zone(s) running for a post-purge?

In an ideal world, the thermostat would have two lines coming from it. One for a call for heat, and one for "I'm close, let me coast to it". And then the main system would have controls that react to be aggressive and then go into the "economy" mode (as these newer aquastats call it) that lets the water temp fall to a lower level.

To get there, this is where I'm leaning at the moment. I have a little time to decide. Might order by the end of the week if I am satisfied to go that way.

1. Hydrostat 3250 should allow for multiple efficiencies on the boiler side. The whole "let me track how long the zones (any/all zones as I only pass a single TT from the ZRC) take from call to satisfied" and then adjust boiler temps from there is not a bad approach. Certainly a simple one to implement. But- I'd like to know more about it. Specifically, does it "reset" after a few hours?

I'm thinking about night time setbacks and morning recoveries. It would make sense to run at lower temps in the eve and then spike high in the am for recoveries- if the system tracks that kind of usage over a few days. It can taper off after the initial recovery hour(s)

2. Possibly use an additional power circuit and the relay McGiever linked for our main living area. It is set warmer than the others. I can set the thermostat a few degrees lower than our desired temp, let it satisfy and coast for say 10 minutes? Have to trial and error that.

The downside of the lower thermostat setting is the drop to the lower temp before the zone runs. Have to think about that a bit.

***
If I were starting with a fresh system, I may just design my own stuff (ala Sting, LOL), but without using the pre-designed stuff, I may not understand it all as well.

I have a feeling I'm going to eventually end up with a custom system. Who knows, maybe I'll put together an Arduino or Raspberry Pi based system. If anyone is interested in this, drop me a PM. I've used them a bit, but not a pro...yet, LOL!

***

So keep the ideas coming! Probably make a choice by the end of the week

What do you think of the temperature based solution idea that I suggested above? Instead of a timer based one.
It can be tricky to find one time interval for each that will give desired results consistently, where as pipe temperatures can/will be more consistent time after time.
Do let me know if this has any appeal, as I have a temperature switch in mind to recommend.

And on a side, I am using a method to accomplish your task just by coincidence.
I added a couple sections of fin tube base board piped in series with 1/2" PEX tube on a separate zone pump (no thermostat) powered by an Grunfos Alpha circulating pump that runs 24-7 at 9 watts to heat a smaller well insulated lower elevation in the house. Excess heat moves freely up an open staircase to Main living area above.
This has proven to keep this lower finished area, which is otherwise a pretty chilly area, very comfortable until it get's to 60-65* outside for a few days straight then it will tend to over heat the entire house. So, yes, the upstairs zone requires less heat now due to the slow and steady supply of heat from below.
But, as you might guess, this lower zone running 24-7 sends pulses of varying temperature heat to the series base boards which just happens to "clip" the higher peaks in the boiler after a heat call ends and then zone "dumps" that heat slowly into that lower base board zone. Of course, YMMV, as all homes are different, but this is working for me. BTW: Main area upstairs is one zone using forced air by way of a water to air heat exchanger.

McGiever wrote:What do you think of the temperature based solution idea that I suggested above? Instead of a timer based one.
It can be tricky to find one time interval for each that will give desired results consistently, where as pipe temperatures can/will be more consistent time after time.
Do let me know if this has any appeal, as I have a temperature switch in mind to recommend.

Ideally, temperature based is best. My primary loop circulator doesn't run 24/7, which would make it easier if it did, but lose economy on the other side.

My ideal system would sense the supply and return of each zone, the temp of each room, primary zone temp and outside temp; then run pumps and the stoker as needed. It would also sense the fire band size and run a timer based on that instead of timer as well.

I'd use logic to determine best combination of fire and circulation to reach the desired setpoint, possibly including "pre-emptive circulation" in a zone to hold a setpoint more steadily.

An example of being pre-emptive is if the zone calls for heat 15 mins once every 3 hours at 5 degrees rise, pre-emptive might circulate cooler water for 15 mins every hour to maintain temp and eliminate the need for the every 3rd hour call for heat. No idea if those are accurate numbers.

Build it

and you will be warm

Sting wrote:Build it

and you will be warm

That advice keeps getting wiser and wiser as this project progresses