Radiant Heating repairs - marin & sonoma county
Radiant Heating Repair in Marin & Sonoma
Local Plumbing — Radiant Floor Heating Specialists
If your radiant heated floors aren’t warming, heating unevenly, or causing high gas bills, Local Plumbing provides professional radiant heating repair throughout Marin, Sonoma, and Napa. We diagnose and repair in-slab radiant tubing, manifolds, pumps, mixing valves, thermostats, and boiler-fed radiant systems of every type.
We repair radiant systems built into:
- Eichler slab homes
- Mill Valley hillside homes
- San Rafael and Fairfax remodels
- Tiburon hydronic additions
- Petaluma new construction radiant
- Multi-zone radiant manifolds in Larkspur, Sausalito, and Novato
If your floors are cold, we fix it.
Why Homeowners Choose Local Plumbing for Radiant Heat Repair
Radiant heat isn’t simple plumbing. It’s a hydronic heating system that depends on:
- Correct flow rates
- Proper boiler settings
- Balanced zones
- Clean manifolds
- Working pumps
- Accurate thermostats
- Free-flowing in-slab tubing
- Stable system pressure
Most HVAC and plumbing companies still don’t understand radiant heating. We work on it every week.
We repair radiant systems integrated with:
NTI, Navien, Viessmann, Munchkin, Lochinvar, IBC, HTP, Triangle Tube, Laars, Rinnai, Noritz boilers.
Common Radiant Heating Problems We Repair
- Radiant floors not warming up
- Radiant heat only working in some rooms
- Floors warm in the morning but cold later
- Heat cycling on/off constantly
- Pump running but no heat
- Manifold actuators stuck or seized
- Mixing valve issues
- Boiler not communicating with radiant system
- Thermostat not calling for heat
- Leaks in in-slab radiant tubing (Eichler homes especially)
- Air in hydronic loops
- Low system pressure or failing expansion tank
If the radiant heat in your home is unpredictable, uneven, or completely cold — we can diagnose the true cause.
Radiant System Components We Repair
Your radiant system can fail in many places — our job is to find the exact point of failure.
✔ Circulator Pumps
Brands:
Grundfos, Taco, Wilo, Armstrong, Bell & Gossett
Common failures: seized rotor, bad bearings, low flow, ECM motor failure
✔ Mixing Valves
Brands:
Caleffi, Taco iSeries, Honeywell, Watts
Common failures: sticking, incorrect temperature output, mineral buildup
✔ Radiant Manifolds
Brands:
Caleffi, Uponor, Viega, Roth, Watts Radiant
Common failures: leaking O-rings, stuck actuators, clogged flow meters
✔ Actuators / Zone Controls
24V actuators controlling each radiant zone
Common failures: stuck closed, no signal, burnt out
✔ Thermostats
Brands:
Nest, Ecobee, Tekmar, Honeywell, NuHeat
Common failures: no call for heat, miswiring, sensor issues, software faults
✔ Boiler Integration
Radiant systems often fail because the boiler isn’t set correctly for low-temperature hydronics (common with Navien & older units).
We understand the entire system — not just one component.

Eichler & Slab Radiant Tube Leaks (Specialty Expertise)
Radiant leaks are common in Eichler homes in San Rafael, Lucas Valley, Terra Linda, Mill Valley, and Novato.
Slab radiant failures often include:
- Pin-hole leaks in copper embedded in the slab
- Corrosion from decades of mineral-heavy water
- Old galvanized transitions leaking
- Slab heat zones air-locking
- Low water pressure from micro-leaks
- Water surfacing through floor tiles or lower level walls
We perform:
- Leak detection
- Thermal imaging
- Pressure testing
- Loop isolation
- Above-slab repiping solutions
Many Eichlers require partial or full radiant loop bypasses — we have completed dozens of these projects.
How We Diagnose Radiant Heating Problems
Radiant systems are complex, so our diagnostic process is precise and methodical:
1. Check boiler or heat source
- Temperature output
- Modulation rate
- Outdoor reset
- Low-loss header or closely spaced tees
- Pump speed settings
2. Inspect manifold
- Flow indicators
- Stuck actuators
- Leaks at unions or O-rings
- Air locked loops
3. Measure pump performance
- Flow rates
- Delta-T across distribution
- ECM pump diagnostics
4. Verify mixing valve operation
- Temperature before and after valve
- Sensor and actuator testing
5. Thermostat & zoning checks
- Call for heat
- Relay or zone controller
- Wiring issues
- Power issues
6. Pressure & expansion tank
- Verify system PSI
- Check for slow leaks
- Relief valve issues
7. Loop-by-loop testing
Each individual loop is tested for temperature, flow, restrictions, or leaks.
This is why we are called to fix radiant systems other companies couldn’t diagnose.
Radiant Heating Repair Pricing**
- Standard radiant heat repair: $350–$680
- 4 Zone Manifold rebuild (O-rings, actuators): $450–$1,200
- New ECM circulator pump: $750–$1,200
- Mixing valve replacement: $620–$1250
- Radiant loop purge & air removal: $450–$900
- Thermostat replacement: $250–$550 (depending on brand)
- Tekmar control repair: $300–$750
- Slab leak detection & isolation: $650–$1,800
- Full radiant loop repipe (Eichler): $3,500–$9,500
**All pricing is job-specific depending on complexity.
Real Local Radiant Repair Jobs
Mill Valley — Radiant Floors Cold in Living Room
Cause: Stuck actuator + air in loop
Fix: Replaced actuator, purged loop
Total: $480
San Rafael Eichler — Leak in Radiant Slab
Cause: Pin-hole leak beneath slab
Fix: Loop isolated + new above-slab radiant run installed
Total: $6,200
Petaluma — Grundfos Pump Failure
Cause: Seized rotor, no circulation
Fix: Installed new ECM Grundfos Alpha pump
Total: $780
Tiburon — Mixing Valve Failure
Cause: Caleffi valve stuck at low temp
Fix: New mixing valve + system recalibration
Total: $920
Service Areas
Marin County: Mill Valley, Tiburon, San Rafael, Sausalito, Fairfax, Corte Madera, Larkspur, San Anselmo, Novato
Sonoma County: Petaluma, Cotati, Rohnert Park, Sonoma, Glen Ellen, Penngrove
Napa County: Napa, American Canyon
Radiant Heating FAQ
Why are my radiant floors not warming up?
Usually due to air in the loops, a failed pump, stuck actuator, or incorrect boiler temperature settings.
Why is only one room warm?
Often a stuck actuator, closed flow meter, or blocked loop.
Can radiant systems leak under the concrete?
Yes. Eichler homes especially have copper tubing embedded in the slab that corrodes with age.
Can radiant leaks be repaired without tearing up the whole floor?
Often yes. We can isolate individual loops and repipe only the affected area.
Does radiant heat need annual service?
Yes — pumps, valves, boilers, and manifolds all require maintenance for peak performance.
Book Radiant Heating Repair
Local Plumbing is one of the North Bay’s most experienced radiant heating companies.
- Radiant specialists
- Boiler integration experts
- Eichler slab leak experience
- Same-day appointments available

Call, text, or book online — we’ll get your radiant heat working properly again.
