No Hot Water Controls problem

cozmicray

Days ago no domestic hot water at tap, primary reset does nothing
burner does not come on at all --Power to unit OK

EFM boiler to hotwater baseboard radiators
Tankless hot water from domestic hot water loop in furnace
Power vent Tjernlund HST-J (120V + 24V)

Old controls (operation fine until week ago - no hot tap water)
Honeywell R8184G oil Primary
Honeywell L8124 A Aquastat

Current controls
Honeywell R7284 oil Primary (New)
Honeywell L8124 A Aquastat

Wired per manual
Power feed L1 (black) L2 (white)
with:
Limit on R7284 to B1 on L8124
Nothing ----- burner does not fire (Limit open)

Rewire disconnect B1
connect Limit on R7284 to L2
(TT CLOSED) (Limit CLOSED)
Burner runs --- heats water -- never stops (until Power OFF)

=================

other obsevations / tests
aquastat L8124
NO relay action
(except when heat thermostat shorted aquastat relay pulls in)
B1 and B2 always have 120V (reguardless of relay position)

Bottom line
How do I wire these up to get tap hot water
and have boiler cycle (ON ? OFF) as normal to keep tap water between 120 - 160 deg?
??? is the aquastat BAD ???

Tnx

STEVEusaPA

It’s wired wrong. For starters take the limit off of L2. How is the Tjernlund wired in with all of this?
A drawing of how you wired it would help so we can correct errors.

cozmicray

If limit is NOT connected to L2 nothing happens
Vent is ON all the time power applied
(yet to figure out how to wire vent -- maybe to "Valve")
(24V control wires to/from vent a mystery right now)

Some wire diagrams
1. Original wiring
2. Wire with new burner control
(this per mfg diagram)
Burner control has L1, L2 Feed to keep alive
Limit to B1
No burner operation wired like this

3. Mfg diagrams for burner control, aquastat








I'm close to kresgeville in NEPA

STEVEusaPA

Can’t really see/blow up your wiring diagram, but I doubt that is how it was wired. Your picture doesn’t show the limit wired to L2. And if wired the way it is shown, the burner runs whether the fan is running and draft is proven or not, which is wrong.

Generally if your primary control does not need constant power (diagnostics, post purge) you want B1 from your aquastat to go to the fan proving switch, and come back to your primary control black wire. Sometimes I see them wired conventionally and the orange wire from the primary goes to the fan proving switch and comes back and is wire nutted to burner motor and transformer.

If you have a modern primary control, you need constant power on L1, which comes from the same wire connected to L1 on the aquastat. B1 on the aquastat goes thru the fan proving switch and comes back to Limit on the primary control.
In either case, if the fan proving switch doesn’t make (close), the burner will not (should not) run.

cozmicray

Thanks for the help
I'll try to provide good info
but I am stumped

I would like to have power ON the oil burner control because that is the way it's suppose to be -- able to read display when oil burner is NOT running.

Which one do you need larger? (URLs below)

The first diagram is exactly how it WAS wired -- I can send photos!!!
Second diagram shows wiring per middle picture in third diagram, in mfg directions
If I change connection to, LIMIT to L2 burner fires upon applying power

??? The only time the relay in aquastat toggles is when heat thermostat is shorted --- never ever in all other tests.

There is always 120V across B1 and B2 never changes.
I would think aquastat sensor when low water temp, pull in relay start firing when sensor high water temp open relay shut down the fire.

Neanderthal way
Gonna put a string on switch up to shower flip switch ON
when water gets cold flip it OFF when water gets hot
(my dog gets too excited and just pees instead of flipping switch)

oil burner control R7284
https://customer.honeywell.com/resources/Techlit/TechLitDocuments/69-0000s/69-2467EFS.pdf

aquastat L8124C
http://www.republicsupplyco.com/SpecSheets/60-2061.pdf


ARGH!

STEVEusaPA

The 'click' you hear in the aquastat is most likely the circulator relay, and it will close (should close) when t-t is jumpered (calls for heat) if the boiler temperature is above the low limit setting.
B1 will have power when the boiler temperature is below the low limit on the aquastat, or there is a call for heat and the boiler temperature is above below the high limit.

Maybe you damaged one of the components by wiring it incorrectly. Connecting the limit to L2 is wrong. Surprised you didn’t instantly fry something. Maybe you did?
A competent pro could properly test all components and replace if necessary and properly wire.
You are creating a possible run away burner situation which could be very dangerous either by destroy the boiler or severely scalding someone.
You need a separate black wire, the same one L1 in the aquastat pigtailed and run to L1 on the primary control for constant power. Usually I run a 3 wire between the aquastat and primary.
From disconnect, black and white go into aquastat. White on L2.
Black gets wire nut with a short black wire to L1 on aquastat, and the red wire from the primary. The red wire on the other end goes on L1 on the primary and that’s your constant power to the primary.

lchmb

If your low limit is set to 160 and your not getting power to B1 with a cold boiler it sounds to me like you have a bad aquastat. Works on a call for heat because it's working on the high limit... or do you have your T-stat wired to the new primary?

cozmicray

BOLD not shouting just to show my response

STEVEusaPA said:

The 'click' you hear in the aquastat is most likely the circulator relay, and it will close (should close) when t-t is jumpered (calls for heat) if the boiler temperature is above the low limit setting.
I can see the relay get pulled in on shorting TT
, does relay also get pulled in by temp sensor in aquastat?
B1 will have power when the boiler temperature is below the low limit on the aquastat, or there is a call for heat and the boiler temperature is above the high limit.

You say
B1 will have power when the boiler temperature is below the low limit .... and the boiler temperature is above the high limit.
B1 has power when temp below limit and above high limit
So B1 has NO power above low limit and below high limit
which I would think is when B1 should be powered firing boiler???

Maybe you damaged one of the components by wiring it incorrectly. Connecting the limit to L2 is wrong. Surprised you didn’t instantly fry something. Maybe you did?


A competent pro could properly test all components and replace if necessary and properly wire.
What test equipment and wiring diagrams would I PRO have that I DON'T?


You are creating a possible run away burner situation which could be very dangerous either by destroy the boiler or severely scalding someone.
Been there done that --with limit tied to L2 (the only way to get burner to run) I let water temp go up to 180
(while watching analog Temp and pressure gauges)
aquastat did nothing -- state of B1, B2 didnot change at High temp --- boiler relief valve squirted out some water
(surprised -- I thought it would open at higher temp)
when water temp below 120 (set low limit) aquastat showed NO change

You need a separate black wire, the same one L1 in the aquastat pigtailed and run to L1 on the primary control for constant power. Usually I run a 3 wire between the aquastat and primary.
From disconnect, black and white go into aquastat. White on L2.
Black gets wire nut with a short black wire to L1 on aquastat, and the red wire from the primary. The red wire on the other end goes on L1 on the primary and that’s your constant power to the primary.

Right now switched feed L1 and L2
wired to aquastat L1 L2,
wired to L1, L2 on Vent,
wired to L1 , L2 on burner primary

so power is available to all componets

what will connection will power burner ON/OFF
to regulate hot water?

cozmicray

??? aquastat operation (L8124A)?? Is this correct?

Aquastat should send signal to fire burner
1. when heat thermostat closes calling for heating
2. when water in domestic hot water loop goes below low limit

Aquastat should remove signal stop burner
1. when heat thermostat opens heat is at / above temp
2. when water in domestic hot water loop goes above high limit

What is signal from aquastat to primary oil burner control to turn it ON/OFF?

Does the relay in aquastat toggle to control signal?
Is relay double pole single throw?
What is double pole for?
What tells circulator pump to go ON/OFF?

Tnx

Jamie Hall

I still can't figure out enough about what's going on to really help all that much.

However...

In most hot water heating systems with domestic hot water thrown in, you have one or more heating thermostats plus an aquastat for the domestic hot water. In your situation, the boiler has to be kept hot enough for the DHW, and that is the job of the DHW aquastat. All it should be is a simple switch -- no power to it. If the boiler is too cool for the DHW, it should close and complete the circuit with T_T on the burner control and the burner should fire. When it warms up enough, it should open and the boiler should quit.

Now. You also need hot water for heating. There may -- or may not -- be another aquastat for that. If there is, it too is a simple switch, but it will be in series with either the end switch on a zone valve (or valves) or it will be in series with the normally open contacts of a relay which is controlled by the space comfort thermostat. In the first instance, when the end switch closes on the zone valve and the boiler is too cool for heating, there should be a circuit from T through the aquastat and the zone valve end switch and back to the other T, turning on the burner. In the second instance, the circuit will be through the normally open contacts of the relay, which are closed by the thermostat.

STEVEusaPA

There is a mistake in my last post, which I edited.
B1 will be (should be) energized when:
-Aquastat temp is below the low limit setting. Burner runs for domestic hot water, up to low limit setting plus differential, or if problem with aquastat, up to high limit.
-During call for heat any time aquastat temp is below high limit.

All I can tell you (again) is it’s wired wrong. You should get a competent tech to make sure the safeties on the controls weren’t damaged, and then wire everything correctly, and test the limits and the safeties.

We’ve been talking about it going on 4 days now and it’s between a 1 and 2 hour job...

cozmicray

The thrill of victory close
wired this way Now
Cycles between Low Temp and High temp
Got Domestic Hot water

B1 tied to limit (per mfg wiring diagram)

**** Power vent runs continuously
safer to run all the time ( instead of Not at all)

How to wire up power vent so it will
shut down after XX sec purge?

shorting A < B does nothing
24 V to A B does nothing



Power Vent mfg instructions at:
https://www.tjernlund.com/Tjernlund_8504060.pdf

Almost only good in Horseshoes, Hand Grenades, Atomic weapons

Tnx

cozmicray

Problem solved, lots learned, replaced parts in wrong order,
Aquastat bad
Here is current working system
the vent pressure switch is in series with CDS cell
No pressure no resistance so burner shuts down
Vent wired up to come on with burner motor
it has 45sec ON after burner shut down

DHW Heat all work

Thanks for the help