Lattner Boiler Company WLF 9.5 HP Instruction Manual page 24

McDonnell Miller Servicing
G.
Disconnect all power to the boiler.
The boiler should be cool and drained of all water
just below the McDonnell Miller control.
Make sure all water is drained from the McDonnell
Miller control by opening the control blowdown
valve.
Disconnect the wiring and conduit connection to the
McDonnell Miller. Tag all wires to ensure they are
reconnected properly.
Remove the eight bolts holding the operating
mechanism to the McDonnell Miller body. Use a
9/16" wrench or a crescent wrench.
It may be necessary to tap near the base of the
operating mechanism to free it from the body.
Lift the McDonnell Miller operating mechanism out of
the body. Be careful to avoid damaging the float and
float arm which extend into the body of the
McDonnell Miller.
Carefully scrape the old gasket from the body and
the operating mechanism of the McDonnell Miller.
Remove any scale in the McDonnell Miller body.
Always check the operating mechanism for any
scale that might be blocking the float or float arm.
Check the float for any holes. H old the float
submerged in a bucket of water and look for any air
bubbles coming from the float.
Always reassemble the McDonnell Miller operating
mechanism to the body with a new gasket.
Reinstall the eight bolts to the operating mechanism.
Draw up the bolts evenly to prevent damage to the
gasket, body or operating mechanism. Do not over
tighten the bolts.
Reconnect the McDonnell Miller per wiring diagram.
Reconnect all power to the boiler.
Use a steel rod or a hard brush and clean inside of
the piping.
16. Flush out all piping with water after cleaning.
17. Replace all pipe plugs and pipe caps. Tighten with
a wrench enough to prevent water or steam leaks.
18. Reconnect power to the boiler.
/B
Gasket
Operating
Mechanism
8 Bolts
Req'd
Body
Cleaning Interconnecting Pipe
H.
(McDonnell Miller)
1. Disconnect all power to the boiler.
2. The boiler must be cool and drained of water below
the level controls.
3. Make sure all water is drained from the McDonnell
Miller or auxiliary low water cut-off control by
opening the blowdown valve.
4. Clean all interconnecting piping by removing the
pipe plugs or pipe caps. Remove all 1
with a 13/16" wrench or a crescent wrench.
Remove the pipe caps with a pipe wrench.
23
Terminal Strip
/ andSwitch
� Housing
11
pipe plugs