The Lyric LYR18 / LYR24 / LYR30 from Monessen
No chimney and no household power. The Monessen Lyric is a contemporary vent-free gas burner listed as an unvented room heater and as a vented decorative burner, in three sizes: the 18" LYR18 at 28,000 BTU/hr on natural gas (27,000 on propane) for a fireplace interior at least 25" wide at the front, 11" deep and 12" high, and the 24" LYR24 and 30" LYR30 at 37,000 (36,000) for interiors at least 30" and 34" wide, 11" deep and 13" high. A self-powered millivolt valve lit by an auto-spark ignitor runs it through a power outage, and it ships with its Onyx fire glass — two bags on the 18" and 24", three on the 30" — with Bronze, Diamond or Sapphire glass as an upgrade. from $999.
Choose the Lyric if you already have a masonry fireplace, a UL127 factory-built fireplace or a listed vent-free firebox and want a clean linear flame through glass instead of logs, without a chimney run, a gas conversion or an electrical circuit. Match the size to the fireplace interior — 25" of front width for the 18", 30" for the 24", 34" for the 30", all 11" deep — and to the heat you want: 28,000 BTU/hr from the 18" or 37,000 from the 24" and 30". The millivolt valve keeps working when the power is out, takes a wall switch, thermostat or hand-held remote, and the same burner runs vented with the damper clamped open if a mantel or wall clearance cannot be met.
It is not right for a bedroom or bathroom — an unvented heater is barred from either room, and Massachusetts bars it there regardless of size. It is not a primary heat source: it takes its combustion air from the room, adds moisture to it, and needs a room of at least 50 cubic feet per 1,000 BTU/hr (1,400 cubic feet for the 18" at full input, 1,850 for the 24" or 30"), so a very tightly sealed house without added ventilation, or a small closed room, is the wrong place for it. It is also not a stand-alone appliance: without a masonry fireplace, a UL127 factory-built fireplace or a listed vent-free firebox that meets its minimum interior there is nothing to install it in, an interior shallower than 11" will not take it, a glass-door lip taller than 3" in front of it is not recommended by the manufacturer (and a listed vent-free firebox takes no glass door or barrier at all unless its own listing approves one), and it must never run with glass doors closed.
Specifications
The fireplace or firebox interior must be at least 25" wide at the front, 20" at the rear, 11" deep and 12" high for the 18" burner; 30" front, 24" rear, 11" deep and 13" high for the 24"; and 34" front, 24" rear, 11" deep and 13" high for the 30" — with the burner against or as near as possible to the rear wall. A glass-door frame or lip in front of the burner changes the depth: no restriction needs 11", a 0"-3" lip needs 16", and anything taller is not recommended (the manual writes that table for a vented installation — a listed vent-free firebox takes no glass or barrier at all unless its own listing approves one). The sides of the opening stay 16" from a combustible wall and the ceiling 42" above it. The wall directly above the opening must be heat-resistant material at least 1/2" thick: 12" or more of it needs no hood on any size; between 8" and 12" the 18" needs no hood but the 24" and 30" must extend the material to 12" or add the adjustable canopy; under 8" the 24" and 30" extend it to 8" and add the canopy, or extend it to 12". A combustible mantel is set by how far it projects: on the 18" with no hood, 2-1/2" of projection sits at least 14" above the opening, 6" at 20-1/2", 8" at 24-5/8" and 10" at 28"; on the 24" and 30" with no hood a mantel projecting 10" or less sits at least 28" above the opening over 12" of heat-resistant material; with the canopy on any size, 2-1/2" at 8", 6" at 14-1/2", 8" at 18-5/8", 10" at 22-1/2" and 12" at 26" — Figures 3.4 to 3.6 on page 11 of the manual draw each profile, and if a clearance cannot be met the burner runs vented with the damper clamped open. The burner sits at least 1-3/8" above combustible flooring that comes within 14" of the fireplace base, or lower when 14" of slate or marble separates the two; vinyl to the wall calls for 14" of floor protection. Gas pressure is 5.0" w.c. inlet minimum and 3.5" manifold on natural gas (7.0" recommended), 11.0"-13.0" inlet and 10.0" manifold on propane (12.0" recommended), through the right-rear inlet; the 18" burner weighs 20 lb, the 24" 22 lb and the 30" 25 lb, and every size anchors to the floor with three screws.
Features
- Contemporary linear burner with a multi-peak flame rising through a bed of fire glass — two bags of Onyx on the 18" and 24", three on the 30", in the carton
- Dual listed: an unvented room heater (ANSI Z21.11.2) or a vented decorative burner with the damper clamped open (ANSI Z21.60)
- 28,000 BTU/hr on the 18" burner or 37,000 on the 24" and 30" (natural gas), with an ODS safety pilot that shuts the burner down if room oxygen drops
- No household power: a self-powered millivolt valve lit by the auto-spark ignitor at the press of the control knob keeps working through an outage
- Remote-ready — an optional hand-held remote, wall switch or thermostat wires straight to the valve terminals
- Anchors to the floor of a masonry fireplace, UL127 factory-built fireplace or listed vent-free firebox with the bracket and three screws in the box
Answers to common questions
What’s included, what’s required, and what’s optional?
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Included in the box: Lyric contemporary burner assembly with cover, ODS safety pilot and auto-spark ignitor module; Onyx fire glass media — two bags on the 18" and 24" burners, three bags on the 30" (the full bed the burner is designed for); Flex gas connector with 1/2" T-handle shutoff valve on the valve inlet; Anchoring bracket and three anchoring screws; UL listing to ANSI Z21.11.2-2016 and ANSI Z21.60-2017 / CSA 2.26-2017; HHT limited warranty — 5 years on the burner.
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Required to complete the installation, purchased separately: Fireplace or Firebox - a solid-fuel masonry fireplace, a UL127 factory-built fireplace or a listed vent-free firebox whose interior meets the minimum dimensions for the size chosen; Gas Line - a supply line run and purged by a qualified installer or licensed plumber, with a regulator upstream if line pressure exceeds 1/2 PSIG (an external regulator is required for propane).
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Optional: C-CLAMP damper clamps (carton of 6) - only if the fireplace forces you to run it vented. Vent-free, the burner works without them and the damper stays under your control; if the wall or mantel clearances cannot be met the manual sends you to a vented installation with the chimney and damper open, and there the clamps are required; RCB on/off remote, TSST thermostat remote, TS thermostat sensor, HILOKTN / HILOKTP variable-flame remote kits and the RRCM receiver cover; the CABL adjustable canopy (the hood the clearance tables call for when the heat-resistant facing above the opening is under 12"); C-CLAMP damper clamps for vented use — the burner operates fully without any of them.
Which size should I choose?
Measure the inside of the fireplace or firebox first, then decide how much heat you want. The 18" burner needs an interior at least 25" wide at the front, 20" at the rear, 11" deep and 12" high and runs 28,000 BTU/hr on natural gas or 27,000 on propane; the 24" needs 30" front, 24" rear, 11" deep and 13" high and runs 37,000 or 36,000; the 30" needs 34" front, 24" rear, 11" deep and 13" high at the same 37,000 or 36,000. The 24" and 30" share a rating and a mantel profile, so between those two the choice is how much of the opening you want the flame to fill. If a glass-door frame or a lip sits in front of the burner in a vented installation, the interior must be 16" deep instead of 11", and a lip over 3" is not recommended; a listed vent-free firebox takes no glass or barrier unless its own listing approves one. All three sizes install the same way and take the same controls.
Where can it be installed — and where can't it?
Inside a solid-fuel masonry fireplace, a UL127 factory-built fireplace whose instructions do not exclude unvented gas logs, or a listed vent-free firebox — never free-standing, and never in a bedroom or bathroom. The interior must meet the minimum for the size (25" front width, 11" deep and 12" high for the smallest), the room must not be a confined space (50 cubic feet per 1,000 BTU/hr — 1,400 cubic feet at the 18" burner's full input, 1,850 at the 24" or 30"), and it needs to be out of high-traffic and drafty areas with curtains, furniture and other flammable objects at least 36" from the front. Above 2,000 ft the input is derated 4% per 1,000 ft, and a manufactured home is fine where local codes allow it.
Does it need a chimney, and what does dual rated mean?
No chimney is needed for vent-free use: the burner is listed as an unvented room heater and an ODS safety pilot shuts it off if the oxygen in the room drops. The same burner is also listed as a vented decorative burner for a solid-fuel fireplace with a working flue — run it that way when a mantel or wall clearance cannot be met, or when you prefer the moisture to go up the chimney. Vented, the damper must be clamped fully open with a damper stop (the C-CLAMP damper clamps sold below the cart — the stop is not in the carton), the flue opening must be at least 29 square inches, the chimney is professionally cleaned first, a thermostat is not allowed, and the heat-resistant-material and mantel rules no longer apply. Massachusetts requires the damper permanently removed or welded open and bars a vented gas log from bedrooms and bathrooms.
Does it need electricity or batteries?
No household power is needed on any size or fuel: the millivolt gas control is a self-powered combination valve that does not require 110 VAC, so the burner keeps working through a power outage. The pilot is lit by pressing and holding the control knob at IGN while the auto-spark module sparks it; that module holds a battery (the manual's parts list calls it the battery module and its maintenance chart lists the auto-spark battery as replace-as-needed), and if the ignitor ever fails the pilot can be lit with a match. An optional wall switch, thermostat or remote wires to the valve's TH and TP/TH terminals with 18 AWG cable up to 15 ft.
How high must a mantel or shelf above the opening be?
That depends on the burner size, how far the mantel projects, and whether the adjustable canopy (hood) is installed — and the wall directly above the opening must be heat-resistant material at least 1/2" thick first. With no hood, a mantel over the 18" burner sits at least 14" above the opening if it projects 2-1/2", 20-1/2" at 6", 24-5/8" at 8" and 28" at 10", over 8" of heat-resistant material; over the 24" or 30" a mantel projecting 10" or less sits at least 28" above the opening over 12" of heat-resistant material. With the canopy on any size the heights drop to 8" at 2-1/2", 14-1/2" at 6", 18-5/8" at 8", 22-1/2" at 10" and 26" at 12". Figures 3.4, 3.5 and 3.6 on page 11 of the installation manual draw each profile; Tables A and B on pages 9-10 say when the hood or more heat-resistant material is required, and if a clearance cannot be met the burner runs vented with the damper clamped open. Send us your mantel depth and we will check the figure with you.
What controls and remotes work with it?
Every size and fuel uses the same millivolt valve, so the same options fit all of them. Monessen sells the RCB hand-held on/off remote with battery receiver, the TSST touch-screen thermostat remote, the TS thermostat sensor, a wired wall switch, and the HILOKTN (natural gas) or HILOKTP (propane) kit that adjusts flame height from a hand-held remote; the receiver piggy-backs on the valve terminals, and mounting it in a wall or under the RRCM insulated cover keeps fireplace heat from shortening its battery life. A thermostat of any kind is allowed only in a vent-free installation.
How does the warranty work if something goes wrong?
Hearth & Home Technologies backs the Lyric with its limited warranty: 5 years on the burner, 2 years on valves, pilots, modules, remotes and wall switches, 1 year on other parts, transferable to a later owner of the home and printed in full on pages 23-24 of the manual. The Torch Guys is an authorized Monessen dealer, so buying from us does not affect it — keep your invoice and the model and serial number from the rating plate in the burner's control area, and we handle the claim with the manufacturer for you.
