Astria Sirius: electronic pilot, the parts that fail, and the altitude catch

Astria builds linear, modern-looking gas fireplaces, the long low flame people pick instead of a traditional box. The Sirius is a top-vent, sealed direct-vent fireplace made by Innovative Hearth Products (IHP) in a 42-inch and a 54-inch width. Everything below comes from IHP’s Sirius installation and operation manual (P/N 900079-00, Rev. D, 12/2016), which covers the Sirius42TEN, Sirius42TEP, Sirius54TEN and Sirius54TEP.

Find the model first

The rating plate tells you the width and the gas type, and the gas type decides which valve, pilot assembly and orifice the unit takes. Photograph it, along with the control compartment behind the lower access door, and send both with your request. That turns the ranges on this page into a number.

The pilot is electronic, which changes the diagnosis

Owners often describe a Sirius problem as “the pilot light needs a new gas valve”, because on an older fireplace that is a fair guess. On a Sirius it usually is not, because there is no standing pilot:

• Intermittent pilot ignition. An ignition board (IHP calls it the DFC board) sparks the pilot when you call for flame, a flame sensor proves the pilot, and only then does the valve open the main burner. No thermocouple, no thermopile.
• Power. The manual recommends 110-volt line power and allows four AA batteries in a backup holder for outages. On batteries the fireplace does flame on and off only; the blower needs line power.
• The remote. A remote and wall-switch receiver are included with every model and are the only way to run it. The manual is explicit that the valve settings cannot be adjusted by hand.
• The CPI/IPI switch. It switches the pilot from on-demand to continuous. The manual’s fix for a burner that lights and then goes out is to switch to continuous pilot, wait two minutes, and relight, so the vent can establish draft. A cold chimney run on an October morning is exactly that situation.

What to check before anyone quotes a valve

IHP’s troubleshooting table for these units, in order:

1. Nothing happens at all. Wall plate set to REMOTE, fresh batteries in the remote and the wall receiver, backup batteries, breaker on, gas shutoffs open. A Sirius can have three shutoffs: the main at the house, one in the control compartment, and sometimes another near the fireplace.
2. It sparks but the burner never lights. Gas not reaching the unit, loose wires at the valve or the ignition board, or air in the line after gas work elsewhere in the house.
3. It lights, then goes out. Draft not established (the CPI trick above), loose wiring, a pilot flame that is not engulfing the flame sensor, or a blocked vent.

The first item is yours to check. Everything past it means opening the control compartment on a gas appliance, and the manual says installation and repair should be done by a qualified service person. If you smell gas at any point, stop, leave the house, and call your gas utility from outside.

The valve itself is a SIT/Proflame electronic valve with 3/8-inch NPT inlet and outlet and test ports on its face, so a technician can read inlet and manifold pressure directly. On natural gas the manual calls for 5 to 10.5 inches water column at the inlet and 3.5 at the manifold; on propane, 11 to 13 at the inlet and 10 at the manifold. A valve gets replaced when pressures and the ignition sequence say it has failed, not because the pilot will not light.

The altitude catch in northern Colorado

The manual approves the standard burner orifices (#37 on the 54-inch natural gas unit, #43 on the 42-inch) for 0 to 4,500 feet. Above 4,500 feet it requires the input to be reduced, either by gas the utility has derated or by a smaller orifice under the National Fuel Gas Code, and it notes the flame shrinks about 4 percent per 1,000 feet of altitude.

Fort Collins and Loveland sit at 4,997 feet and every other town this site covers is higher than 4,500, as the permits and altitude page lays out town by town. A Sirius that went in with its sea-level orifice and was never adjusted tends to show it as soot on the glass or a lazy or yellow flame. Checking the installed orifice is part of our first visit on any Sirius.

One more manual detail people miss: during the first few fires a white film on the glass is normal burn-in, and IHP says to clean it after each of those early fires once the glass is cool, or it bakes on. See white film or haze on the glass.

What fails, and what it costs

Ranges are the published ones on the pricing page; the repair cost estimator works them out by symptom. If your Sirius clicks with no flame, start with clicks but will not light; if it lights and drops out, shuts off after a few minutes. Brand pages for Heat & Glo and Heatilator, Napoleon and Regency, and Majestic, Monessen and remotes cover the other badges we see most.