Replies

1. 
   BillHartmann | Oct 14, 2006 04:21am | #1

   Here is the schematic for the L8148.

   http://hbctechlit.honeywell.com/request.cfm?form=60-2278

   That is from a Canadain site, but it should be the same.

   There is no L3 terminal. Only L1 and L2 which should have 120 V.

   With the thermostat disconnected you should have about 24 V AC on T,T. If not them the transformer is bad.

   There is a terminal 3, but not L3. And by default a jumper between L1 and 3.

   Look at fig 2 and 5.

   The about the only way that you could have burned out the transformer would be to put 120 on T,T. And possibly the relay.

   1K is the relay coil and 1K1 and 1K2 are the relay contacts.

2. 
   DanH | Oct 14, 2006 04:27am | #2

   > It was running fine until I tried to test the t-stat by quikly touching the wires to the boiler t t terminals.

   Ever heard "If it ain't broke, don't fix it"?

   Odds are you burned something out. First candidate is the thermostat transformer, but, since there's 120V floating around that you may have crossed up, anything is possible.

   Please explain precisely:

   1) Why did you feel it necessary to test the thermostat?

   2) What thermostat were you testing, a wall thermostat or the aquastat?

   3) Precisely which wires/terminals did you touch together?

   If Tyranny and Oppression come to this land, it will be in the guise of fighting a foreign enemy. --James Madison
1. 
   redtoolbox | Oct 14, 2006 04:37am | #3

   It was a wall thermostat I was testing to see if the wires were broken and I touched the white and red t-stat wires to the TT terminals on the aquastat. i tried other t-stat and they did not work either. Also my volt meter does not calibrate under 120v should I get another tool to measure?
   thanks dave

1. 
   BillHartmann | Oct 14, 2006 04:47am | #5

   What kind of voltmeter do you have that does not "calibrate under 120 volt". Does it just have a couple of lights or a bar that moves. Yes many of that type are only for use in check for the presents of 120 or 240 volts, but a few will also indicate 24 v.What you want is on that has either a meter (analog) or digitial display.But if you have 120 on L1/L2 and just jumpering between T,T does not produce a click (although I am not sure how loud it is on that unit) then either the transformer or relay is bad.

2. 
   DanH | Oct 14, 2006 04:50am | #6

   If the voltmeter won't adjust below a 120V range then likely it's a "wiggy" style and will have difficulty reading the 24V. Can you see graduations on the meter scale for 25, 50, and 75V? 24V should get up almost to the 25V graduation. If the scale only really starts at about 50V then you need a different meter.But try this. Disconnect both wires from T-T and then use a short jumper wire to connect the two (T-T) terminals together. If neither the circulation pump nor the burner starts then the Aquastat is probably hosed, assuming that you were correct about L1-L2 having power.

   If Tyranny and Oppression come to this land, it will be in the guise of fighting a foreign enemy. --James Madison

1. 
   redtoolbox | Oct 14, 2006 05:51am | #7

   I think I need a new meter. But I did jump the TT and I did get the circ pump and power venter working. Based on this limited info what parts should I buy to get this going.
   thanks dave

1. 
   DanH | Oct 14, 2006 05:56am | #8

   Now connect two wires from T-T to the thermostat terminals. If the thermostat doesn't start the unit up, then you need a new thermostat.(Of course, this assumes you're using the right thermostat terminals. How many terminals are on the thermostat?)

   If Tyranny and Oppression come to this land, it will be in the guise of fighting a foreign enemy. --James Madison

2. 
   redtoolbox | Oct 14, 2006 03:20pm | #9

   Thanks for your help Dan. It was the thermostat. I must have blown 2 tstat and finally tried a third and it worked. It is 48 degrees in the house right now and were off to the diner. hopefully it will be warm when I get back.
   thanks again,
   dave brown

3. 
   DanH | Oct 14, 2006 04:43am | #4

   Yeah, based on that diagram, if you have about 120V betweenm L1 and L2, and you don't have close to 24V between T and T (with one of the thermostat wires disconnected), then the transformer or (very slight possibility) the relay in the Aquastat is burned out.

   Note that 24V will not be enough to light a neon tester, and may not be enough to move a "wiggy", and you may have to switch ranges on a voltmeter to see it clearly.

   If Tyranny and Oppression come to this land, it will be in the guise of fighting a foreign enemy. --James Madison