The usual suspects
Air trapped in the loop
Air pockets stop circulation cold — radiators heat at the bottom but stay cold up top, often gurgling.
A failed circulator pump
The boiler makes hot water; the pump moves it. Silent or humming pump = nothing travels.
Low system pressure
Below ~12 psi, upper floors stop heating and many boilers lock out entirely.
A stuck zone valve
One cold zone with others fine points at its valve or thermostat, not the boiler.
Boiler homes are worth doing right.
Pumps, air bleeds and pressure fixes — done properly, priced before we touch anything.
Book My Same-Day Visit60 seconds online · or call (206) 486-6373
Worth trying first (5 minutes, free)
- 1
Check the pressure gauge: roughly 12–15 psi cold is healthy on most homes.
- 2
Bleed a cold radiator if you have a key: air hisses out, water follows, close it. Top-floor first.
- 3
Feel the pump: gently — a running pump has a slight hum and vibration. Silence is a clue.
- 4
One cold zone? Check its thermostat before blaming the boiler.
Still not working? Then it’s a technician job — and the sooner it’s booked, the sooner the house is comfortable again. Book the visit →
Stop and book a pro if…
- Pressure at zero — or climbing past 25–30 psi.
- Repeated lockouts with error codes.
- Water anywhere around the boiler.
- Kettling — a rumble like a giant kettle (its own guide below).
Why homeowners hand it to us
- You approve the price first. Upfront quote before a single screw turns.
- Same-day service. Book in a minute, hear from a tech within 1 business hour.
- 500+ jobs done by 4.9★ rated, professional technicians.
- Fixed right, guaranteed. If it’s not right, we make it right.
Quick answers
Can I keep bleeding radiators every week?
Bleeding that becomes routine means air keeps entering — a leak, a bad expansion tank or a failing air separator. Fix the source once instead of bleeding forever.
The boiler itself is hot. Doesn’t that mean it works?
It means it MAKES heat — the failure is in delivery: pump, air or pressure. Good news: delivery-side repairs are usually the affordable ones.
Do you actually service boilers?
Yes — hydronic heat is part of our heating work across Puget Sound. Book online; price upfront as always.
Done guessing?
Radiant heat is the best heat — when it moves. Book the fix and get it moving.
Book My Same-Day Visit60 seconds online · or call (206) 486-6373
More: all problems · heating service · AC service · 24/7 emergency