A vacant Maryland house with fire sprinklers: what to do with the system between owners.

A sprinklered house sits empty more often than people think. A parent passes and the estate takes a year to settle. An investor buys a 2010 colonial in Howard County and spends four months renovating it. A tenant leaves a Prince George’s County townhouse in November and the next one arrives in March. A family relocates and the house lists in winter. In every one of those cases somebody has to decide what to do with a life safety system that was designed for a house with people in it. Most of them decide by accident.

Know which system you have before touching a valve

There are two kinds of 13D systems in Maryland houses, and shutting off the water means something different in each. A standalone system has its own riser and control valve off the water entry. Close the domestic main and the sprinklers may or may not still be fed, depending on where the tee sits. A multipurpose system shares its piping with the domestic plumbing; the sprinkler heads hang off the same network that feeds the bathrooms. Close the main and the sprinklers are off too. Our how sprinklers work guide shows you how to tell them apart at the riser. Find out which one you have first. Everything below depends on it.

The three ways owners handle an empty house

• Keep it live and heated. The water stays on, the sprinkler control valve stays open, and the thermostat holds a temperature that keeps every pipe above freezing. This is what the system was designed for and what most insurers assume. It costs heat and it costs the small risk of a plumbing leak with nobody home to hear it. For a house that will be shown to buyers or has contractors in it every day, this is the right answer.
• Water off, heat on. Common on flips during demolition and on estates that want to stop paying for water. Understand what you have given up: on a multipurpose system, and on most standalone systems where the sprinkler tee sits downstream of the main, the sprinklers are now dry and the house has no fire protection. The days a house is most likely to burn are the days a contractor is soldering pipe or grinding in the basement. If the water has to be off for the trades, have them turn it back on when they leave.
• Drained and winterized.The full shutdown, usually for a house that will sit unheated through winter. On a sprinkler system this is a licensed contractor’s job, not the plumber’s. The system has to be drained at the right low points, dry heads and antifreeze loops handled correctly, and the whole thing refilled, pressure checked and inspected before anyone occupies the house again. The county permitted this system as a condition of the house being lived in. Restoring it is not optional, and a written record that it was done properly is what the next buyer’s inspector will ask for.

What the insurer cares about

Read the vacancy clause on the policy before the house has been empty long. Most homeowner policies limit or drop coverage after a set number of days without an occupant, typically 30 or 60, and the replacement is a vacant dwelling policy with its own conditions. Those conditions almost always speak to water: either the heat is maintained or the plumbing is drained. A frozen pipe burst is the single most common claim on a vacant house, and on a sprinklered house the sprinkler pipe is part of the plumbing in the insurer’s eyes. Tell the carrier the house has sprinklers. Some will write the vacant policy on better terms because of it, and none of them want to learn about the system after a loss.

Flips: the four things that go wrong

We see more sprinkler problems from renovations of vacant houses than from any other cause, because nobody on site owns the system. Four of them account for almost everything.

• Painted heads. A sprayer crew paints a ceiling and the heads with it. A painted head is a dead head and has to be replaced, not cleaned. Our painted heads guide covers how to mask and what replacement involves.
• Struck heads. A ladder, a drywall sheet or a demo bar hits a head and it opens. On a live system that is a flood in a house nobody is watching. Our article on accidental discharge covers the first hour. Head guards on exposed basement heads during demo are cheap insurance.
• Buried heads. A new soffit, a dropped ceiling or a closet built under a head, and the head is now behind drywall. Every wall or ceiling change in a sprinklered house needs a sprinkler permit alongside the building permit. Skip it and you have created the exact problem our unpermitted work article describes, on a house you are about to sell.
• Changed supply. A new water softener, a whole house filter or a pressure reducing valve installed on the main ahead of the riser changes the water the system was designed on. See low water pressure for why that matters at the final.

One person on the job should own the sprinkler system. Tag the control valve, photograph every head before demo, and put the sprinkler contractor on the schedule before the drywall crew, not after.

Estates: find the paper first

An executor inherits a system and no knowledge of it. Start with the paper. The original permit and final live at the county. Annual inspection reports, if the owner had them done, are usually taped to the riser or in the folder with the furnace manuals. The backflow assembly, where the utility requires one, has its own test record. If the folder is empty, book a checkup before the listing goes live. A written inspection report, with a $150 backflow test where one is due, turns an unknown into a line item and takes the sprinklers off the table in negotiation.

Wells and power

A well fed system in Carroll, Frederick or northern Baltimore County depends on a tank and a pump, and the pump depends on power. An estate that cuts the electric service to save money has also cut the sprinkler supply. If the power must go off, treat the system as drained and follow the winterization path above. Our well water guide explains how the tank and pump package works.

Before anyone moves back in

• Control valve open and locked or tagged, gauge reading normal pressure.
• Every head counted against the finished layout, none painted, none buried, none struck.
• Backflow assembly tested if the utility requires it and the test is due.
• Any drained system refilled, pressure checked and inspected by a licensed contractor, with a report.
• Any wall, ceiling or supply change permitted and closed out with the county.

A sprinklered house that sat empty for six months is not a problem. A sprinklered house that sat empty for six months with nobody watching the system is a problem that shows up on the buyer’s inspection. Decide on purpose, write down what you did, and have the system checked before the keys change hands.