EFM install completed. Help needed with the aquastat

Finally completed the install of the EFM 520 highboy last nigh around 6:00 and for the life of me I can not figure out why motor will not turn on when the temp. drops below my lo setting on the L8124A aquastat.

I have the hi set at 180 the low at 160 and the differential setting at 10

I do not have a thermostat (Jumper installed)

The circulator is wired to run 24/7

The stoker motor is wired to B1 B2

The only way I can get the boiler to run is by setting the timer to run for three minutes every eight minutes.

By using the timer I am able to keep the boiler at 140 degrees

If you have the aquastat and timer wired according to the EFM directions, it is time to try another aquastat. With the TT terminals jumped, it should start the stoker anytime the water temperature is below the high limit (minus the high limit diff.).

As for the TT terminals being jumped, that is simply a bad idea. If the high limit fails in the aquastat you will have a very "hot" boiler.

-Rob

If this is still the old mechanical relay system, you can excite the relay manually and proof its operation to close the B1 B2 terminal. Measure voltage at B1 - Is it there? Is C1 C2 closed? if yes then B1 and B2 will be open. This is a poor control device at best for a solid fuel appliance but its cheep.

Whats wrong with jumping the TT points???? The likelihood of the relay failing closed is about as remote as hitting the lottery, and it provides far better boiler control - depending on the rest of the system control.

Wouldn't the burner relay have to be functional in order for the timer to activate the stoker? I am assuming the timer is connected to the ZR terminal of the L8124A...but assumptions usually don't work out well. smtm, can you explain how the controls are wired in greater detail?

Sting, I agree that the chances of that relay sticking are slim, the boiler in my house was wired that way when I moved in. Aside from short cycling off the high limit all the time, it worked fine. I changed it after a friend of mine lost a building from a fire in the boiler room. The inspection determined that a relay had stuck in one of the controls. Perhaps the inspector didn't find the real root cause, but it was enough to motivate me to rewire my boiler controls. Sorry if I made it seem like a problem was imminent from the TT terminals being jumped.

-Rob

I do not have a thermostat (Jumper installed)

If there is no thermostat and the t-stat terminals are jumped then how is the temperature in the building controlled?

Wood'nCoal wrote:If there is no thermostat and the t-stat terminals are jumped then how is the temperature in the building controlled?

by the zone pump(s) circulation on demand, like they should - controlled by their respective wall/zone stats. The boiler with the TT points jumped just sits at its set point (above condensing temperature) and waits for demand, reacting to vessel energy and temp as its used - or (better) tie the TT points to an outdoor reset (like a 256 Teckmar) and allow the boiler temp to adjust up from 140 as outside temps drop and load demand increases -

IF you only have one zone - one tstat - one pump - one small load, then sure - use the Triple A as designed

It depends!

More sprinkles on the donuts please

I understand, but smtm says:

The circulator is wired to run 24/7

It sounds like the controls are wired incorrectly, or a faulty aquastat.

no details were given as to why

maybe its the primary loop pump

or maybe its the boiler loop pump from the outhouse to the heat exchanger on the load

or maybe


Oh me! back to donuts and cup size exploration

Wood'nCoal wrote:I understand, but smtm says:

The circulator is wired to run 24/7

It sounds like the controls are wired incorrectly, or a faulty aquastat.

The circulator is wired to run 24/7 since I will not be able to run control wires from my house to the boiler (which is located 75' from the house in a seperate out building) until spring

With the circulator wired to the aquastat the circulator is shut down when the high temp is reached.

When the 110 volt stat in the house calls for heat, it turns on the furnace fan only and heat is extracted via the heater coil installed in the return side of the duct work.

I purchased the boiler from scrapper jr and the controls are brand new.

What really has me confused

When I first fired up the unit the stoker and fan worked as they should, upon reaching the high temp limit (180) the stoker shut off.

When the temp dropped to the low temp setting (160) the stoker did not come back on.

The temp continued to drop down to 110 at which point I started to use the timer to control the stoker.

Is it possible the controls are bad?

smtm wrote:
The circulator is wired to run 24/7 since I will not be able to run control wires from my house to the boiler (which is located 75' from the house in a seperate out building) until spring

With the circulator wired to the aquastat the circulator is shut down when the high temp is reached.

When the 110 volt stat in the house calls for heat, it turns on the furnace fan only and heat is extracted via the heater coil installed in the return side of the duct work.

We may need to visit about what you wrote above.

Understood why your circulating 24/7 - many outhouse systems do this very well.

I wonder why you would want to stop circulation when hi temp is achieved ??? are you referring to boiler firing maybe?

with out circulation when the boiler is hot; how does the coil in the house recharge with energy ?

Sting wrote:

smtm wrote:
The circulator is wired to run 24/7 since I will not be able to run control wires from my house to the boiler (which is located 75' from the house in a seperate out building) until spring

With the circulator wired to the aquastat the circulator is shut down when the high temp is reached.

When the 110 volt stat in the house calls for heat, it turns on the furnace fan only and heat is extracted via the heater coil installed in the return side of the duct work.

We may need to visit about what you wrote above.

Understood why your circulating 24/7 - many outhouse systems do this very well.

I wonder why you would want to stop circulation when hi temp is achieved ??? are you referring to boiler firing maybe?

with out circulation when the boiler is hot; how does the coil in the house recharge with energy ?

I was trying to explain why I set up the circulator to run 24/7

I want the circulator to run 24/7 for excatley the reason you stated above

O

rereading in that light -- yes me bad

ok how about the proofs I suggested ??? All in order?

I purchased the boiler from scrapper jr and the controls are brand new.

I know you did, I believe you picked it up last Saturday. Now I understand, you are using a line voltage t-stat in the house to run the furnace fan, the boiler runs on the aquastat and the circulator pump always runs. Stoker motor wired to B1 and B2. Got it.
Read all about the aquastat:
http://customer.honeywell.com/techlit/p ... 5-6571.pdf
With the t-stat terminals jumped and the boiler water at the high limit temperature or above the stoker should start when you reach the low end of the differential, that is your high limit setting minus the fixed 10° differential. See page 7 of the manual, "Relationship of setpoints and differential". I'm starting to confuse myself here...would someone with a functioning brain please proofread this for me?
A side note, I'd run 170° low/200° hi.

Sting wrote:If this is still the old mechanical relay system, you can excite the relay manually and proof its operation to close the B1 B2 terminal. Measure voltage at B1 - Is it there? Is C1 C2 closed? if yes then B1 and B2 will be open. This is a poor control device at best for a solid fuel appliance but its cheep.

Whats wrong with jumping the TT points???? The likelihood of the relay failing closed is about as remote as hitting the lottery, and it provides far better boiler control - depending on the rest of the system control.

There is no voltage at B1 or B2 (with the temp below the low temp settings), unless the timer is activated.