How Can I Make This Work.

I am installing My KA-6 boiler, I decided to use the Grundfos Alpha pump with Zone Valves. Grundfos says the Alpha should be powered at all times and it will stop attempting to move water when all zone valves close and the pump "dead heads". I am using a Taco ZVC-405-4 Zone Valve Controller, and the Keystoker came with a Honeywell L8124-A Auqustat. My question is how do I make this system stop trying to heat when the water temperature drops below the low setting on the Honeywell aquastat? Ive considered "jumping" the Thermostat input on the Honeywell and powering the Taco zone valve controller with the circulator output, then if the water temp drops below set point it will interupt power to the valve controller.

So what you want is boiler protection - YES???

then wire an Aquastat such as pictured [ either a strap on or well type if you have a port]
into the circuit that supply power to the pump

Wire it to OPEN on temperature drop and set it to open appx 140 - 145 degrees

THERE - the pump will not run and the zones will not circulate should the boiler need a little recovery time

Sting wrote:So what you want is boiler protection - YES???

then wire an Aquastat such as pictured [ either a strap on or well type if you have a port]
into the circuit that supply power to the pump

Wire it to OPEN on temperature drop and set it to open appx 140 - 145 degrees

THERE - the pump will not run and the zones will not circulate should the boiler need a little recovery time

Boiler protection is what I'm looking for, however, I do not want to turn the pump off and on. I'm using a Grundfos Alpha, Grundfos says it should be powered on at all times otherwise it will lose its memory for the "auto adapt" feature. The Honeywell aquastat keystoker provided has the capability to interrupt the power to the circulator in the event of low temperature. I had the thought maybe I could use that to power the Zone valve controller.

sure you could
but if you use that then that same control will quiet the boiler when the circulator is running
check it out
the sequence of events is
the boiler fires
temperature rises till set point
control interrupts boiler fire and starts circulator
Circulator runs till water drops to set point

Repete

Stupid control for solid fuel - your mileage may vary

so is you don't want to stop the pump [ I get that now - old and forgetful me] them let the pump do its thing and interrupt another part of the distribution system - such as the low voltage call for heat from the loads/zones

or

well I think you got an handle on this

Sting wrote: interrupt another part of the distribution system - such as the low voltage call for heat from the loads/zones

That was my thoughts behind using the circulator output on the Honeywell to power the Zone valve controller. When the boiler temperature dropped too low it would cut power to the zone valve controller. I need to know if their is a way to make this happen with the controls I have already.

Sting wrote:sure you could
but if you use that then that same control will quiet the boiler when the circulator is running
check it out
the sequence of events is
the boiler fires
temperature rises till set point
control interrupts boiler fire and starts circulator
Circulator runs till water drops to set point

I don't know if im missing something or not...

My plan was to use the circulator power output on the Honeywell aquastat to power the Zone valve controller. In order to to this I would have to put a jumper wire on the thermostat input of the Honeywell so that it would send power to the zone valve controller at all times, unless the water temp dropped below the low setting at which point it would interrupt power to the ciculator power output (turning off the zone valve controller). In other words I would be telling the Honeywell that their was a constant demand for heat and it would leave what it thinks is a circulator running. The room thermostats would tell the zone valve controller when they needed heat.

all that jumper wire does is eliminate control of the boiler from a single house thermostat
and the boiler becomes somewhat autonomous of the load [ and that's a good thing IMO]
BUT
The algorithm of the triple aqusstat sequence will not change with this jumper

In my world - I tear those triple a's off as fast as I can and replace them with a simple single stage control that [then] functions only as a safety for over run [ ill wire it to open on temperature rise - set at 210] and I control the boiler temperature with an outdoor reset

but thats a whole other can of worms

ummm without invoking the hate and wrath of someof my "friends' on these pages

may I suggest a little reading on the heating help web site under controls

Boots wrote:My question is how do I make this system stop trying to heat when the water temperature drops below the low setting on the Honeywell aquastat? Ive considered "jumping" the Thermostat input on the Honeywell and powering the Taco zone valve controller with the circulator output, then if the water temp drops below set point it will interupt power to the valve controller.

That function is built into the Honeywell aquastat. Read the manual for the control, I believe it shuts off @ the low limit and won't allow a restart without a 10° rise in temp.

coaledsweat wrote:

Boots wrote:My question is how do I make this system stop trying to heat when the water temperature drops below the low setting on the Honeywell aquastat? Ive considered "jumping" the Thermostat input on the Honeywell and powering the Taco zone valve controller with the circulator output, then if the water temp drops below set point it will interupt power to the valve controller.

That function is built into the Honeywell aquastat. Read the manual for the control, I believe it shuts off @ the low limit and won't allow a restart without a 10° rise in temp.

Correct, but it does this by cutting the power to the circulator. The pump I've chosen (Grundfos Alpha) needs to be powered at all times to see benefit of its features.

I started reading the book that came with the honeywell aquastat, it appears the model I have has built in control for Zone relay. It looks to me based on the schematics that it is also switched off/on with the low limit. Maybe I can use that to control my zone valve controller without having to jump the thermostat input (I did not like that idea anyway...)

lets look at it in this manor

think of your system as two separate parts and control them seperatly

the boiler as the energy source and control it only to respond to the other part - in no way should it want or need to control the load - it only responds to it

and the house or load or the rooms or the zones and control all that independently

revisit primary secondary controls

Try this on for size

Wire the TT terminals together on the triple a of the boiler or wire them to the output of an outdoor reset - your choice
leave the BB terminals wired to the "burner' or in this case the stoker unit
remove everything from the CC terminals and turn the screws tight

power the triple a off a master disconnect switch that controls ALL the heating system

From that main disconnect wire a fused switch to power your groundfoooooooosssssss pump - there it runs anytime it sees head pressure drop anytime the system is on

from the main disconnect - wire a fused switch to what ever controls you have powering the zone valves and thermostats - there you have control of energy distribution

now for boiler protection you need a single throw aquastate sampling the boiler temperature wired in-between the burner control and the burner [ stoker] set to open on temperature rise - set apps 210
and you need another [as above] sampling the same vessel set to open on temperature drop that will interrupt power of the circuit powering your zone valves and load t stat zone set at 145

when the boiler over temps - power to the stoker is interrupted
when the boiler under temps and is in jeopardy of condensing - power to the zone valves is interrupted just as if the zone thermostats stopped calling for heat - or you can also wire the close side of this same switch to your dump zone control

BTW -- if you install an outdoor reset - you will set the triple a on the boiler to 210[ish] and let the ODR do its job - then you can eliminate the overtemp aquasate I described above

Kind Regards
Sting

This is all quite interesting, but why not just wire the Alpha w/ a standard male cord cap [male plug] and plug it into a nearby wall outlet? Or extend from the boiler circuit and add a outlet box.
That does what you need...KISS.

Sting wrote:Try this on for size

Keystoker supplied an aquastat for Over temp, It will be installed and functional. and If I understand the schematics to the Honeywell Aquastat I can achieve what you are suggesting by powering the zone valve controller with the "Zone relay control" terminals.

McGiver wrote:
This is all quite interesting, but why not just wire the Alpha w/ a standard male cord cap [male plug] and plug it into a nearby wall outlet? That does what you need...KISS.

That is my plan to power the circulator, I'm looking for a way to keep they system from attempting to heat the house when the water temp gets too low.

I think maybe im doing a poor job of explaining myself

Okay, you want to stop the circulation if boiler water anytime drops below a certain set point.

You can run one side of the 24 vac that supplies power up to the house t'stat(s) and run it from your zone controller and break it in the triple a'stat at the 2 CC terminals and run it back again to the zone controller to where it would of originated at.
CC is a single pole switch to open or prevent power to the zone valves if/when the boiler water temp is below the low set point, regardless of any t'stat heat calls zone valves will not open .