need help on boiler wiring thermostat doesn't work
#1
need help on boiler wiring thermostat doesn't work
Hi,
I just installed a williamson GWA seriers-2 boiler,
with RB-24E Low Water Cut-Off
Honeywell L4006E aquastat
the plumber has installed all the piping and I connected all the wire. the problem is the boiler runs find , the heat is coming out from the baseboard, and the boiler stop once it hits the high temperature, but the thermostat can't control the boiler which mean can't turn off the boiler. it looks like the boiler start even I do not connect the T T to the thermostat. attached is the wiring, please help to check, thanks in advance.
I just installed a williamson GWA seriers-2 boiler,
with RB-24E Low Water Cut-Off
Honeywell L4006E aquastat
the plumber has installed all the piping and I connected all the wire. the problem is the boiler runs find , the heat is coming out from the baseboard, and the boiler stop once it hits the high temperature, but the thermostat can't control the boiler which mean can't turn off the boiler. it looks like the boiler start even I do not connect the T T to the thermostat. attached is the wiring, please help to check, thanks in advance.
#2
Hard to understand that drawing,what are the 2 thermostats?there must be some other boiler control.
What controls the circulator and zone valves?
Geo
What controls the circulator and zone valves?
Geo
#3
attached is the wiring diagram provided by boiler, I have followed the instruction, just do not know why it doesn't work. I test the LWCO it works, just do not know why the thermostat doesn't work.
please help to check
please help to check
#5
That drawing is hard to read,have you tried disconnecting L4006 aquastat it appears that you may have it in parallel with the room Stat.as NJ asked what is the purpose of the L4006?
Geo
Geo
#6
The full size diagram can be found in the manual on the Williamson website if you want to see full size.
Yes, if there is in fact an indirect water heater on the system, and that 4006 is controlling the temperature in that tank, it IS in parallel with the thermostat, more or less... and this may in fact be why the boiler is running, if the water tank is not 'satisfied' yet.
My guess is that the system was turned on after installation and the tank was being heated... and it was not understood that the boiler would fire until the tank came up to temperature regardless of the setting of the thermostat.
Yes, if there is in fact an indirect water heater on the system, and that 4006 is controlling the temperature in that tank, it IS in parallel with the thermostat, more or less... and this may in fact be why the boiler is running, if the water tank is not 'satisfied' yet.
My guess is that the system was turned on after installation and the tank was being heated... and it was not understood that the boiler would fire until the tank came up to temperature regardless of the setting of the thermostat.
#7
NJ trooper thanks for your reply, Honeywell L4006E aquastat is mount above the LWCO on the riser. there is no other indirect hot water tank. the L4006E is to set the high and low limit for the boiler. and I also found out there is a temp control for the boiler on the control board. so do I still need that L4006E or I can have both. don't know why the boiler runs without thermostat. please help
#8
That does appear to be the case,according to the drawing it look's like the DHW (L4006) would take priority over the room stat,the installer should have explained that to the customer.
Cheers!
Geo
Cheers!
Geo
#10
Have you tried disconnecting the L400E,and see what happens, according to the manual there is a boiler temp sensor already connected to the control module ,have you contacted the installer for assistance?
Geo
Geo
#14
Let's slow down a bit... one thing at a time.
First, the 4006 aquastat.
Where you have it connected to the "DHW" input is incorrect.
It sounds as if the intention of this aquastat is as an AUXILIARY HIGH LIMIT control, being that it is a MANUAL RESET model with the red pushbutton on the front.
Yes, this aquastat is an extra limit control and should be wired in SERIES with the other limits, safeties, and the LWCO.
I don't see a problem with the LWCO wiring, the R and C are the 24VAC power, the other two wires are in the limit circuit and will cut off the burner if the low water is detected.
First, the 4006 aquastat.
Where you have it connected to the "DHW" input is incorrect.
It sounds as if the intention of this aquastat is as an AUXILIARY HIGH LIMIT control, being that it is a MANUAL RESET model with the red pushbutton on the front.
should I connect the L4006 in between the two yellow with LWCO?
I don't see a problem with the LWCO wiring, the R and C are the 24VAC power, the other two wires are in the limit circuit and will cut off the burner if the low water is detected.
#16
Agreed, the LWOC, look's OK, wouldn't that L4006 be N/C ? In which case that circuit ,as connected,would be constantly calling for heat, as you say it should be wired in series with other safeties.I believe problem will be solved when he removes it from where it is connected now.
Geo
Geo
#18
the boiler is working well now. one more thing, when the boiler hits 180 F, then boiler will turn off and then turn back on 170 F. is it ok for the boiler? the plumber told me, the boiler should turn back on in 150 F.
#19
when the boiler hits 180 F, then boiler will turn off and then turn back on 170 F. is it ok for the boiler?
That temperature difference is called the 'Differential'.
the plumber told me, the boiler should turn back on in 150 F.
MOST boiler controls have a 'differential' in the neighborhood of 10F. Some as small as 8F, a few as high as 15F.
There are some boiler controls that have adjustable differential settings that go as high as 30F, but your boiler does not.
#20
Your boiler has two knobs on it...
BOILER TEMP and ECONOMY ADJUST
You should start out with the Boiler Temp on 180F
and the Economy Adjust at MAX.
This will allow the boiler to use the residual heat and not fire the burners immediately on a heat call if it determines it doesn't need to.
In some cases, the house may cool a bit too much in between boiler firings and if you find this happening, turn the economy setting down a little bit at a time until you feel the temperature isn't dropping too much between burner firings.
Maybe the manual says it better than I can:
BOILER TEMP and ECONOMY ADJUST
You should start out with the Boiler Temp on 180F
and the Economy Adjust at MAX.
This will allow the boiler to use the residual heat and not fire the burners immediately on a heat call if it determines it doesn't need to.
In some cases, the house may cool a bit too much in between boiler firings and if you find this happening, turn the economy setting down a little bit at a time until you feel the temperature isn't dropping too much between burner firings.
Maybe the manual says it better than I can:
BOILER ECONOMY SETTING
To comply with Department of Energy regulations, the control
module circulates available hot water before turning on the boiler
to attempt to satisfy a call for heat. While attempting to satisfy
the heat demand, the control module also monitors the boiler
temperature changes via the temperature sensor and determines
whether or not the available hot water will satisfy the demand,
adjusting the time delay to turn on the boiler until it determines
that additional heat will be needed. The knob labeled ECONOMY
ADJUST provides an adjustment between maximize (MAX) and
minimize (MIN) the delay. The maximum (MAX) adjustment
position should be used to maximize energy savings. Turning the
knob counterclockwise decreases the delay time and should only
be used in the event that the heated space becomes uncomfortable.
• ADJUST ECONOMY TO DESIRED POSITION (MAX ISTHE
PREFERRED SETTING).
To comply with Department of Energy regulations, the control
module circulates available hot water before turning on the boiler
to attempt to satisfy a call for heat. While attempting to satisfy
the heat demand, the control module also monitors the boiler
temperature changes via the temperature sensor and determines
whether or not the available hot water will satisfy the demand,
adjusting the time delay to turn on the boiler until it determines
that additional heat will be needed. The knob labeled ECONOMY
ADJUST provides an adjustment between maximize (MAX) and
minimize (MIN) the delay. The maximum (MAX) adjustment
position should be used to maximize energy savings. Turning the
knob counterclockwise decreases the delay time and should only
be used in the event that the heated space becomes uncomfortable.
• ADJUST ECONOMY TO DESIRED POSITION (MAX ISTHE
PREFERRED SETTING).
#22
Thanks Kylin, happy holidays to you too...
One more thing I think I forgot to mention: The L4006E should be set about 20-30F ABOVE the high limit setting on the boiler control. You don't want it set too close in order to avoid 'nuisance tripping'. It should only ever trip if the boiler control fails and continues to fire the boiler to too high a temperature.
Good Luck!
One more thing I think I forgot to mention: The L4006E should be set about 20-30F ABOVE the high limit setting on the boiler control. You don't want it set too close in order to avoid 'nuisance tripping'. It should only ever trip if the boiler control fails and continues to fire the boiler to too high a temperature.
Good Luck!