Las Vegas boiler repair — combi + hydronic + radiator systems
Boiler repair for wall-hung combi boilers, condensing boilers, cast-iron radiator systems and radiant floor heat. Circulator pump, expansion tank, low-water cutoff, zone valve, and ignition diagnostics from certified technicians.
1. CIRCULATOR PUMP FAILURE: pump that moves hot water through the loop stops or seizes. Symptom: heat call but no warmth from radiators. Replacement: $350-$650 with pump swap.
2. EXPANSION TANK: bladder inside tank fails, system pressure spikes and safety valve dumps water. Symptom: puddle under boiler, pressure gauge climbing. Replacement: $220-$380.
3. LOW WATER CUTOFF: safety switch that shuts down the boiler when water level drops. Failed switch either causes false shutdowns or (dangerous) fails to shut down when needed. Replacement: $280-$450.
4. IGNITION SYSTEM: pilot assembly, ignitor, or gas valve. Similar to furnace failures but at boiler pressures. Replacement: $180-$650 depending on part.
For combi boilers, add flow sensor and DHW plate exchanger to the common failure list. For older cast-iron systems, add zone valves and thermostatic mixing valves. Full diagnostic covers everything.
Diagnostic + repair
The service call
How your Las Vegas HVAC install or service call works — four steps, no surprises
Live response
Boiler no-heat calls prioritized winter, same as furnace calls. Arrival window disclosed on phone. Live technician on the line.
Diagnostic
Circulator pump function test, pressure gauge check, expansion tank test, ignition sequence, water quality assessment. Combustion analysis on the burner.
Written quote
Line-item pricing for parts + labour + parts warranty. Diagnostic fee credited on repair proceed.
Repair + verify
Part replaced. System pressurized to spec (typically 12-15 psi cold, 20-25 psi hot). All zones tested. Air bled from radiators. Return water temperature verified below condensing threshold on high-efficiency units.
Repair vs replace
Cast-iron boilers can run 50+ years — modern boilers 15-20
Older cast-iron boilers (pre-2000) commonly run 30-50 years. That kind of longevity means repair almost always makes economic sense — even a $1,500 repair on a 40-year-old boiler beats the $8,000-$12,000 replacement cost when the unit will keep running for another decade.
Modern high-efficiency condensing boilers have shorter expected lifespans — 15-20 years typical, sometimes shorter in hard-water Las Vegas areas. Repair math on modern boilers looks more like furnace math: over 50% of new-boiler cost + 12+ years age = replace.
For boilers under manufacturer warranty (typical 12-15 year heat exchanger warranty on high-efficiency condensing), repair is almost always the answer — the parts are covered. We handle the warranty claim paperwork if applicable. Related in Las Vegas: furnace repair.
Las Vegas HVAC repair boiler repair questions answered
Diagnostic: $149. Circulator pump: $350-$650. Expansion tank: $220-$380. Low water cutoff: $280-$450. Ignition module: $180-$450. Combi boiler flow sensor: $220-$380. Full-system flush and rebalance: $450-$650. Straight pricing before any work.
Yes. Normal cold boiler pressure is 12-15 psi. Hot operating pressure is 20-25 psi. If cold pressure is above 15 psi and climbing, the expansion tank has failed and the pressure relief valve is going to dump water eventually. Fix ASAP to prevent water damage.
Most common: pressure relief valve dumping because expansion tank failed (see above). Second most: leaking circulator pump seal. Third: leaking gasket at a flange. Photo-diagnose sources; some are simple $200 fixes, others indicate boiler replacement time. Call and we'll diagnose same-day.
Cast-iron boilers can genuinely run 50+ years. If yours is heating well and combustion analysis is clean, preventive replacement rarely makes economic sense — you'd sacrifice years of reliable service. Reactive replacement when a major failure occurs is usually the right approach. That said: efficiency gain from modern condensing units means gas bill savings that pay back replacement cost.
High-efficiency condensing boilers typically carry a 12-15 year heat exchanger warranty and a 1-5 year parts warranty on other components. Cast-iron boilers 15+ years old are out of warranty. We check warranty status during diagnostic and file claims when applicable.
Radiators cold on the second floor. Diagnosed a seized circulator pump for the upstairs zone, replaced same visit, heat back on within 3 hours of the call. Straight pricing.
M. Silvestri
Circulator pump swap
★★★★★
Puddle under the boiler was scary. Turned out to be a failed expansion tank causing the pressure relief to dump. Replaced tank, no more leaks, no water damage. Simple fix once diagnosed.
F. Kowalski
Expansion tank fail
★★★★★
Newer Navien combi wasn't producing hot water reliably. They diagnosed a stuck flow sensor, replaced it under warranty (heat exchanger warranty covered it), just paid labour. Reliable hot water since.
L. Fournier
Combi flow sensor
★★★★★
Old cast-iron boiler had a burner issue. Half a dozen other companies quoted us on replacement. These folks said 'it's got 15 more years in it easy' and fixed the burner for $340. Turned out they were right.
T. Petrov
50-year cast-iron
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