A wet-base design, a horizontal tube, and a two-pass heat exchanger makes this one of the best-designed, best-heating boilers on the market.
Swing Out burner door
The low water content provides heat or hot water delivery within minutes of start-up.
Forced draft burner performs with minimal chimney draft.
The compatibility with indirect storage tanks provides enough hot water to meet the comfort requirement of virtually any home.
One-piece boiler construction ensures years of trouble-free service. There are no push nipples or "O" rings to leak.
The compact design saves space, yet it's capable of three firing rates.
We reduce servicing expenses by making the heat exchanger easily accessible from either end.
The 85% AFUE rating is among the highest from today's boilers.
As with all of our boilers, the low mass boiler is manufactured in the USA with American-made steel, IBR tested and rated, constructed to ASME code requirements passing rigorous third-party inspections and hydrostatic tests and is backed by a lifetime limited warranty.
Now Featuring the
Beckett AquaSmart Boiler Control
Beckett AquaSmart Boiler Control
Why Low Mass?
There is a cost (called standby loss) associated with boilers during the off cycles. Reducing standby loss means increasing fuel efficiency. The low-mass concept virtually eliminates standby loss, providing nearly instant heating with less fuel combustion.
Thermo-Dynamics has combined this low-mass concept with the ultra-modern technology of high-efficiency, flame, retention burners that produce a cleaner, more efficient flame. This system ensures maximum efficiency from every fuel dollar.
WATER VOLUME- The low, 5-1/2 gallon water content provides heat and hot water delivery within minutes of start up. The low mass concept reduces standby losses associated with boilers during off cycles and provides nearly instant heating with less fuel consumption.
EFFICIENCY - 83% TO 85% AFUE- The high efficiency obtained with the LM boiler are due to the design to the heat exchanger, a two pass, wet base, Scotch Marine design.
MULTIPLE FIRING RATES - .75 TO 1.10- One boiler can be fired at three different rates, offering versatility and keeping costs low. IBR listed at each firing rate. Each unit is supplied with nozzles and labels for all three rates.
FORCED DRAFT- Forced draft chimney design performs with marginal chimney draft, assuring proper combustion in spite of poor chimneys.
COMPACT SIZE- Standing 19-3/4 inches high, 19 inches wide, and 36 inches long, this compact boiler not only saves space but can easily be installed in areas not approved for other boilers. The LM series is approved for both closet and alcove installation on combustible flooring.
ASME CONSTRUCTED AND IBR RATES- Each boiler is constructed and hydrostatically tested in accordance with ASME Boiler Code. The capacity and efficiency are rated in accordance with the standards of the Institute of Boiler and Radiator Manufacturers (IBR).
LARGER CAPACITIES- The LM 125/150 boiler is available for larger capacities. It features blended firing rates of 1.25, 1.35 and 1.50 GPH.
LIFETIME LIMITED WARRANTY- Unlike other prorated warranties that often cover a small percentage of the cost of a new boiler after the 15th or 20th year, Thermo-Dynamics boiler replacement costs are never more than 50% of the replacement boiler list price.
STANDARD FEATURES - The following built-in features found in all Thermo-Dynamics boilers help increase the longevity of the boiler and make the unit easier to service, ensuring maximum efficiency and performance for the life of the boiler:
Built in "Air Scoop" purges air from the system providing a quiet, trouble free hot water heating system without the use of external devices.
Easy cleaning and maintenance accessibility to combustion areas and the open tubes make it easy for the service technician to thoroughly clean the boiler. The LM-Series can be cleaned from either end by simply removing eight brass nuts. The burner and clean-out door is a hinged, swing-away door. A well-maintained boiler continues to perform at higher efficiency and is less likely to develop service problems.
LMD ETL Listed for DIRECT VENT without Power Ventor. LMD includes above equipment...
plus solid state post-purge burner, back-up high limit control with manual reset.
ASME Code Boiler w/Swing Out Door
Ceramic Fiber Combustion Chamber
Altitude, Temperature & Pressure Gauge
ASME Relief Valve
Built-in "Air Scoop"
3450 RPM Flame Retention Oil Burner
Cadmium Cell Primary Relay
L8148-A Aquastat Relay*
007 Circulator or Equivalent
Brass Boiler Drain
Factory Assembled, Wired & Packaged
Supplied w/3 Nozzles/Firing Rates
* May substitute L4006-A Aquastat
IBR Input #2 Oil GPH
Nozzle w/Pump 140 PSI
DOE Htg. Capacity MBTU/Hr.
Net IBR Rating MBTU/Hr.
Side Wall Direct Vent
Water Content (gal.)
"A" Jacket Length
"B" Overall Length
Shipping Weight (lbs.)
* For LMD Series add 10lbs. to weight.