Radiant Heat Repair in Marin & Sonoma County: What Homeowners Should Know

Conor Crawford • September 24, 2026

Radiant Heat Repair in Marin & Sonoma County: What Homeowners Should Know

Radiant heating is one of the most comfortable ways to heat a home, and throughout Marin and Sonoma counties, there are thousands of homes that rely on hydronic radiant heat every winter.


Many of these systems have been operating for decades.


At Local Plumbing, we work on radiant heating systems throughout Marin and Sonoma County, from older Eichler homes with original in-slab radiant piping to modern multi-zone systems using high-efficiency boilers, pumps, mixing valves, and smart controls.

As temperatures begin to drop around the Bay Area, now is the time to make sure your radiant heating system is ready.


Common Radiant Heating Problems

Radiant heating systems are generally reliable, but because they contain multiple components, a problem with one part of the system can affect an individual room, a heating zone, or the entire house.


Some of the most common calls we receive include:

  • Radiant heat not getting warm
  • Certain rooms or zones staying cold
  • Boiler running but the house isn't heating
  • Radiant system taking too long to heat
  • Noisy pumps or piping
  • Boiler repeatedly turning on and off
  • Low system pressure
  • Leaking manifolds or valves
  • Failed circulator pumps
  • Air trapped in radiant loops
  • Thermostat or zone valve problems
  • Older radiant piping leaking below the floor or slab


The important thing is to diagnose the entire system, rather than immediately assuming the boiler is the problem.


A perfectly functional boiler cannot heat the home properly if there is a failed circulator, closed valve, airlocked loop, control problem, or inadequate water flow.


Why Radiant Heat Repairs Require Specialized Knowledge

Hydronic radiant heating is different from conventional forced-air heating.

Instead of simply producing hot air, a radiant system has to correctly manage water temperature, water flow, system pressure, zoning, and boiler operation.


Depending on the home, the system may include:

  • Boiler
  • Circulator pumps
  • Radiant manifolds
  • Zone valves
  • Mixing valves
  • Expansion tank
  • Air separator
  • Outdoor reset controls
  • Thermostats
  • Heat exchangers
  • In-floor or in-slab tubing


When diagnosing a radiant heating problem, we look at how all of these components are working together.


This is particularly important with older Bay Area homes where a newer boiler may have been connected to a radiant system originally installed decades earlier.


Radiant Heat Problems in Eichler Homes

Marin County has a large number of Eichler and mid-century homes that use radiant heating embedded directly in the concrete slab.

These systems can be extremely comfortable when they're working correctly, but repairing them requires experience with older radiant systems.


One concern with original Eichler radiant systems is aging metal piping beneath the concrete slab.


A radiant leak may show up as:

  • Boiler pressure continually dropping
  • Frequent need to add water to the heating system
  • Unexplained warm or damp areas of flooring
  • Higher water or energy usage
  • A heating zone that no longer performs correctly


Finding the source of the problem before opening flooring or concrete is especially important.


Local Plumbing provides radiant heating troubleshooting and repair throughout Marin County, including communities with significant numbers of Eichler homes such as San Rafael, Terra Linda, Lucas Valley and surrounding areas.


Why Some Radiant Zones Stop Heating

One of the most common radiant heating complaints is:

"Most of the house is warm, but one room or zone isn't heating."


This doesn't necessarily mean there is a problem with the boiler.


Possible causes include a failed zone valve, circulator pump problem, thermostat issue, air trapped in the loop, restricted flow, manifold problem, or a control issue.


The first step should be determining whether hot water is actually being delivered through the affected radiant loop.


Replacing expensive equipment before performing this diagnosis can leave the original problem unresolved.


Radiant Heating System Pressure Problems

A hydronic heating system operates as a closed-loop system and normally maintains relatively consistent pressure.

If the boiler continually loses pressure, there is a reason.


Possible causes include:

  • Expansion tank failure
  • Pressure relief valve discharge
  • Automatic air vent leakage
  • Boiler heat exchanger leakage
  • Valve or fitting leaks
  • Radiant piping leaks


Continually adding water to a heating system without determining where the pressure is going isn't a long-term solution.

Fresh water also introduces additional oxygen and minerals into the system, which can contribute to corrosion and other problems.


Older Boiler With a Radiant Heating System

Many Bay Area radiant systems are still connected to boilers that are 20, 30, or even 40+ years old.

Age alone doesn't necessarily mean a boiler needs to be replaced.

However, homeowners should consider the overall condition of the boiler, availability of replacement parts, operating efficiency, reliability, venting condition, and whether repeated repairs are becoming necessary.

In some cases, repairing the existing boiler makes sense.

In others, upgrading to a modern high-efficiency boiler can improve reliability and provide much better control of the radiant system.

The key is properly designing the new boiler around the existing heating system rather than simply replacing one boiler with another.


Modern Boilers and Older Radiant Systems

Modern condensing boilers can be an excellent match for radiant heating because radiant systems often operate at relatively low water temperatures.

Lower return-water temperatures allow condensing boilers to operate at higher efficiency.

However, the installation still needs to be designed correctly.

Boiler sizing, pumping, flow rates, controls, piping configuration, outdoor reset, and water temperature all matter.

An oversized boiler or improperly configured system can result in short cycling, inconsistent temperatures, excessive equipment wear, and disappointing efficiency.


Should You Service Your Radiant Heating System Before Winter?

Fall is one of the best times to have a radiant heating system checked.

Once the first cold weather arrives in Marin and Sonoma County, heating service calls increase quickly.

A pre-season inspection gives you an opportunity to identify problems before you're depending on the system every day.


Depending on the equipment, a radiant heating and boiler service may include checking:

  • Boiler operation
  • Ignition and combustion
  • System pressure
  • Expansion tank
  • Circulator pumps
  • Zone operation
  • Safety controls
  • Venting
  • Condensate system
  • Radiant supply and return temperatures
  • Visible leaks or corrosion


Annual maintenance is particularly important for modern high-efficiency condensing boilers.


Radiant Heat Repair in Marin & Sonoma County

Local Plumbing provides radiant heating and boiler service throughout Marin and Sonoma counties.

Our team works on both older and modern hydronic heating systems, including boiler repair, boiler replacement, circulator pumps, controls, manifolds, zoning problems, and radiant heating troubleshooting.


We regularly work in communities including San Rafael, Mill Valley, Tiburon, Sausalito, Corte Madera, Larkspur, Kentfield, Ross, San Anselmo, Fairfax, Novato, Petaluma, Sonoma and surrounding areas.


If your radiant heat isn't working correctly—or you simply want the system checked before colder weather arrives—schedule a radiant heating service with Local Plumbing.



Local Plumbing
Boiler & Radiant Heating Specialists
Marin & Sonoma County
415-484-0454

Hand connecting a flexible hose to a wall-mounted tankless gas water heater.
August 5, 2026
Compare tank, tankless & heat pump water heater options for your Tiburon, CA, home. Call (415) 234-0370 for a free quote before the 2027 deadline.
A plumber in a blue uniform and gray gloves uses an orange pipe wrench to tighten a chrome sink
July 6, 2026
Need plumbing services in San Rafael, CA? Local Plumbing is a licensed C-36 contractor with 300+ 5-star reviews. Get upfront pricing. Call today.
underground copper piping showing an obvious failure and water leaking from it
By Conor Crawford • June 29, 2026
A sudden high water bill often means a hidden plumbing leak. Learn the common causes and how Local Plumbing finds hidden water leaks fast.
Plumber in corner of garage area locating the water shut off
By Conor Crawford • June 29, 2026
Learn where your main water shutoff valve is located, when to use it and why every Marin homeowner should know how to stop a plumbing emergency.
By Conor Crawford • June 17, 2026
A Proud Moment for Local Plumbing
A plumber is kneeling on a wet floor searching for a plumbing leak.
By Admin • May 14, 2026
Discover how Local Plumbing detects hidden plumbing leaks in San Rafael, CA, before expensive damage hits. Click here for expert insight and savings!
Close-up of a metal plumbing fitting being tightened with a wrench.
May 14, 2026
Discover essential seasonal plumbing tips for your home in Kentfield, CA, with Local Plumbing. Click here to read more.
A wrench tightening a metal pipe fitting wrapped with thread seal tape.
April 17, 2026
Discover hidden plumbing issues in older San Rafael, CA homes with Local Plumbing. Call 628-237-7654 or click here to learn more about our services.
By Conor Crawford • March 19, 2026
If you’ve heard that gas water heaters are being banned in California in 2027, you’re not alone. At Local Plumbing, we’re already getting weekly calls from homeowners in San Rafael, Mill Valley, Novato, Tiburon, and across Marin County asking: “Do I need to replace my gas water heater right now?” “Will I be forced to go electric?” “What happens if mine breaks after 2027?” Let’s break it down clearly — no fluff, no politics — just real-world guidance from a local plumbing company that installs these systems every day. Is California Banning Gas Water Heaters in 2027? Short answer: Yes… but not exactly how people think. Starting January 1, 2027, new regulations in the Bay Area will require: All newly installed residential water heaters to meet ultra-low (zero) NOx emissions standards In reality, this means: Traditional gas water heaters will no longer be allowed in most replacement situations Electric systems — especially heat pump water heaters — will become the standard The Biggest Misconception (Important) Let’s clear this up right away: You do NOT have to remove your existing gas water heater There is: No forced removal No retroactive ban No inspections coming to your house You can keep your current system running as long as it works. What Happens When Your Water Heater Fails After 2027? This is where things change. If your gas water heater fails after 2027, you will likely: NOT be allowed to replace it with another gas unit Be required to install: A heat pump water heater (most common) Or another approved electric system This is why people are calling it a “ban” — because the change happens at replacement, not before. How This Impacts Marin County Homes Marin homes present some unique challenges: 1. Electrical capacity issues Many homes in: San Anselmo Fairfax Mill Valley …have older panels that may not support a heat pump water heater without upgrades. 2. Tight install spaces Closets Garages with low clearance Under-stair installs Heat pump units are: Larger Require airflow Need condensate drainage 3. Higher upfront costs (but rebates help) Typical comparison: Type Installed Cost Gas tank (today) $3,500–$6,500 Heat pump water heater $6,500–$12,000 BUT: Marin County homeowners may qualify for $2,000–$5,000+ in rebates Lower operating costs over time What About Tankless Water Heaters? This is a big question we get. Gas tankless water heaters (Navien, Rinnai, etc.) are also affected After 2027: New gas tankless installs will likely not be permitted (but not confirmed) Electric tankless is usually not viable in Marin homes due to electrical demand This makes heat pump systems the primary replacement path Timeline: What’s Coming Next 2027 → Residential water heaters affected 2029 → Gas furnaces likely impacted Early 2030s → Broader electrification across homes This is part of California’s long-term push toward building electrification. Should You Replace Your Water Heater Before 2027? This depends on your situation. Consider replacing early if: Your unit is 8–12+ years old It’s showing signs of failure You want a simple like-for-like gas swap Your home is not ready electrically Wait if: Your system is newer and reliable You’re planning a remodel You want to take advantage of: Rebates Newer heat pump technology Local Plumbing’s Recommendation (Real-World Advice) At Local Plumbing, here’s how we’re advising Marin homeowners: Don’t panic — but do plan The worst-case scenario is: 🚨Your water heater fails unexpectedly in 2027 🚨You’re forced into a rushed, expensive electric upgrade Instead, we recommend: ✔ Evaluate your current system lifespan ✔ Assess your electrical panel capacity ✔ Create a planned replacement strategy Why This Matters for Marin Homeowners This isn’t just a regulation — it’s a shift in how homes are built and serviced. And in Marin County specifically: Older housing stock Higher installation costs Strict permitting This transition needs to be handled correctly the first time FAQ: Gas Water Heater Ban (Marin County) Can I still repair my gas water heater after 2027? Yes — repairs are still allowed. Can I install a used or existing gas unit? No — new installations must meet emissions standards. Are there exemptions? Possibly — for: Electrical limitations Certain property types Hardship cases (These are still evolving) Are heat pump water heaters worth it? Yes — when installed correctly. But they must be: Properly sized Installed in the right location Matched with your home’s electrical system Final Thoughts 👉 Gas water heaters aren’t being “ripped out” in 2027 👉 But they are being phased out at replacement For Marin homeowners, this means: ⚠️ Planning ahead is critical 💰 Costs and logistics will change 🔌 Electrical readiness matters more than ever Need Help Planning Your Upgrade? If you’re in: San Rafael, Mill Valley, Novato, Tiburon, Larkspur, Fairfax, or anywhere in Marin County Local Plumbing can help you: Evaluate your current water heater Plan for 2027 compliance Install gas (while still allowed) or heat pump systems Maximize available rebates Call or text Local Plumbing today Local Plumbing is your local Marin plumber
By Conor Crawford • February 23, 2026
When your boiler stops working, it’s not just inconvenient — it can shut down your entire home’s comfort system. At Local Plumbing, we specialize in professional boiler service and repairs throughout Marin County, including San Rafael, Mill Valley, Tiburon, Sausalito, Novato, and surrounding areas. Whether you have a modern high-efficiency condensing boiler or an older cast-iron unit, we diagnose it properly and fix it the right way. Why Boiler Service Is So Important Boilers are different from forced-air systems. They’re pressurized, sealed hydronic systems that require trained technicians to maintain safely and efficiently. Annual service prevents: Loss of efficiency (higher gas bills) Circulator pump failures Air lock issues in radiant systems Ignition and flame sensing problems Heat exchanger damage Leaks at relief valves or expansion tanks Carbon monoxide risks In Marin County, especially in older homes like Eichlers or custom homes with radiant slab heating, neglected boilers can cause serious repair costs if not maintained. Signs Your Boiler Needs Repair Call us if you notice: No heat or uneven heat in zones Boiler making banging or kettling noises Radiant floors not warming properly Pressure dropping below 12 PSI Relief valve dripping Error codes on Navien, NTI, Viessmann, Lochinvar, etc. Pilot light or ignition failure Sudden spike in gas bills Many “no heat” calls we respond to are small issues caught too late — failed sensors, dirty flame rods, or clogged condensate traps. Boilers We Service We regularly service and repair: NTI TRX Series Navien NHB & NCB Lochinvar Noble & Knight Viessmann Vitodens Rinnai boilers Triangle Tube (legacy systems) Munchkin boilers Cast iron Weil-McLain & Burnham If it’s hydronic — we work on it. What’s Included in Our Boiler Service Our full boiler maintenance service includes: ✔ Combustion Analysis We use a combustion analyzer to dial in proper gas-to-air ratio for maximum efficiency and safety. ✔ Heat Exchanger Cleaning Condensing boilers require proper cleaning to prevent efficiency loss and corrosion. ✔ Condensate System Inspection We clean traps and neutralizers to prevent blockages. ✔ Expansion Tank Testing A failed expansion tank can cause pressure spikes and relief valve discharge. ✔ Circulator & Zone Check We test pumps, zone valves, and controls to ensure even heat distribution. ✔ Safety Component Verification We test pressure relief valves, flame sensors, ignition systems, and safety shutoffs. ✔ Radiant System Inspection We check manifolds, air separators, pressure levels, and glycol if present. Emergency Boiler Repair in Marin If your boiler fails in the middle of winter, we provide fast response throughout: San Rafael Mill Valley Tiburon Corte Madera Larkspur Sausalito Novato We stock common repair parts for the systems most commonly installed in Marin homes. When Is It Time to Replace Instead of Repair? We’ll give you honest advice. Replacement may make more sense if: Boiler is 15–20+ years old Heat exchanger is cracked Parts are discontinued Major control board failure on an aging unit Repeated service calls We specialize in high-efficiency condensing boiler replacements and can evaluate whether repair or replacement makes better financial sense. Why Marin Homeowners Choose Local Plumbing Licensed C-36 Plumbing Contractor Hydronic specialists (not just general plumbers) Combustion analysis on every service Experience with radiant slab systems Local warehouse & training facility in San Rafael Clean, uniformed, professional technicians We don’t “just show up and reset the boiler.” We diagnose root causes. Boiler Service FAQs How often should I service my boiler? Once per year minimum. High-efficiency condensing boilers absolutely require annual cleaning. How long does boiler service take? Typically 2-3hrs, depending on system condition. Does boiler service improve efficiency? Yes. Dirty heat exchangers and poor combustion tuning can increase gas consumption significantly. Is boiler maintenance required for warranty? Most manufacturers require documented annual maintenance. Schedule Your Boiler Service Today If your boiler hasn’t been serviced in the past 12 months, now is the time. Serving Marin County homeowners with expert hydronic knowledge and real diagnostics — not guesswork. Local Plumbing Your Local Marin Boiler Experts Call today to schedule service.