Replyare you asking what is needed to accomplish your task?
if so; you may be pushing the envelope of this open forum.
Regular Guest
Here is the scenario.... you have to make this boiler modulate and purge (to at least 100 degrees or less)for under $.
The boiler pictured has a cold start control from the factory. GO!
You can use anything you want and modify anything you want as long as you stay at or below $. wholesale in parts.
(if this isnt allowed please delete)
Last edited by beenthere; 12-24-2012 at 05:48 AM. Reason: price
Professional Member*
are you asking what is needed to accomplish your task?
if so; you may be pushing the envelope of this open forum.
It`s better to be silent and thought the fool; than speak and remove all doubt.
Regular Guest
Yes I am ...not my task... the taskOriginally Posted by dandyme
And ... Am I?
(obviously not talking modulating fire rate)
Regular Guest
49 views and still nothing?. I assume that you are checking it twice and seeing what is naughty or nice?.
Professional Member*
Call somebody else
Seriously though, what do you mean by modulate and purge? Are you talking about a primary/secondary setup where the primary maintains a steady temperature while the secondary modulates somehow? Does purge mean an auto air vent? Is labor and piping materials included in your price? Does everything have to be automatic, or can we have some guy stand there operating manual "modulate" and "purge" valves?
Professional Member* / ARP Committee
I'm up for the task
Officially, Down for the count
YOU HAVE TO GET OFF YOUR ASS TO GET ON YOUR FEET
I know enough to know, I don't know enough
Why is it that those who complain the most contribute the least?
MONEY CAN'T BUY HAPPINESS. POVERTY CAN'T BUY ANYTHING
Professional Member*
Place someone next to the boiler with his/her hand on the on/off switch and a thermometer & turn it on. When the thing, whatever your are measuring) reaches 110 degrees have that person turn off the on/off switch.
"The American Republic will endure until the day Congress discovers it can bribe the public with the public's own money.
- Alexis de Toqueville, 1835
Regular Guest
LOL!~I scared the cat half to death with the snarf I made when I read thisBeer all over the floor...which I have to clean up now
Modulate the out going water at a set temp (lets say whatever you like between 140 and 180) and then purging the remaining water out of the boiler after the call is satisfied.
Seriously though, what do you mean by modulate and purge? Are you talking about a primary/secondary setup where the primary maintains a steady temperature while the secondary modulates somehow? Does purge mean an auto air vent? Is labor and piping materials included in your price?
Reason for doing this is to bring the boiler to temp fast without chilling the element or causing the boiler to shock and then getting all the water top side after the stat is satisfied, rather than losing it to standby.
Material only
Regular Guest
The rest of you are just as funny... HAHAHA
God Speed, Jim. We'll miss you - 2-26-23
Weil McLain BCP 3. Its simple fast and easy.
It will run the circ anytime the outdoor temp is below the heating point, and regulate boiler temp based on outdoor temp.
Won't bring the water temp up fast, as what purging the boiler is counter productive to doing that.
Professional Member*
I'm thinking of various ways but I'm not getting the question completely. A Teckmar could keep a set temp plus with ODR modulate the temp. A bypass would let the boiler heat fast also.
Regular Guest
Ok 60sec go , you need three stats , a bypass ,holding take and a solenoid. When a boiler is turned off some heat remains in the mass of the boiler. If the flow through the boiler is stopped at the same time the boiler is shut off, the residual heat is lost. Therefore, after operation of the boiler the residual heat in the boiler should be purged to the system in order to decrease standby losses. This is accomplished by turning the boiler off but keeping the system pump on for a period of time. This function increases system efficiency by minimizing standby losses.To ensure that the DHW tank is up to temperature after the DHW Setback period the control must raise the tank temperature before the setback period ends. This can be accomplished automatically by using a control that has an optimum start / stop function. This function increases comfort by ensuring the DHW tank is up to temperature at the beginning of the occupied period.DHW priority allows the DHW tank to recover faster by temporarily suspending the heat supply to the heating system. All of the available heat is provided to the DHW tank for a period of time. This function provides more comfort by ensuring faster DHW pick up times and increases system efficiency by often allowing the use of a smaller heat source. OK what did I win....???? lol
Regular Guest
Lets hear more about these three stats.
You win for the explanation of the purge cycle but what if you don't have a DHW tank?. Remember.... no waste (by design) and $. limit on parts.
Last edited by beenthere; 12-24-2012 at 02:01 PM. Reason: price
Professional Member*
I don't remember having to describe how to prioritize DWH loop so you win a cookie or a slap in the face which one? Lol that's a joke we use to use when I was younger.
Regular Guest
Looks like a Logomatic. Is it cheaper than the logomatic?.
Regular Guest
DWH?...
Regular Guest
Bringing the boiler up to temp before allowing that water to exit. This is a pulse supply where the flow is started and stopped and the burner runs continuously until the aquastat set point is made or the call for heat is satisfied. Generally the aquastat is set 20 - 40 degree's above the Purge point setting.
The cross over would be needed to either assist in tempering the return side in order to eliminate shock and increasing the rise within the boiler. It would also be needed on a pulse system to minimize pump stress while the boiler was making, prior to the purge.
The final stage purge would come after the call for heat was satisfied.
Got to go
Professional Member*
DHW, can't you read minds yet lol. What the purpose for the pulse setup? To get the boiler hot before any water is pumped.
God Speed, Jim. We'll miss you - 2-26-23
Don't know, don't know what a logomatic cost.
And since this is an open forum, prices aren't allowed.
Professional Member
Merry Christmas all.
Anytime pulse modulation is discussed I think voltage regulators as that was a big part of my previous day job. I
In this case a TI UC1825 pulse width modulator chip, a few resistors and capacitors and thermistors and you have a state of the art control. Use the UC1825 to control the boiler on-off functions, and instead of the feedback circuit regulating on a voltage, use the thermistors as the control element. Since the 1825 is a current mode device, you can use that inner control loop for a continuous operation type control with the inner control loop running an inverter driving a variable speed pump. Thus burner almost never turns completely off, just the fuel and water flow are regulated in a pulse width modulation scheme.
OP probably wanted something to buy off the shelf though, eh?, not a design tutorial?
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