Question? Just ask us!
Free Encyclopedia of Building & Environmental Inspection, Testing, Diagnosis, Repair
InspectAPedia ® Home
AGE of WATER HEATERS
AIRBOUND HEAT SYSTEM REPAIR by WATER FEED VALVE
ALTERNATIVE HOT WATER SOURCES
ANODES & DIP TUBES on WATER HEATERS
ANTIFREEZE for BOILERS
ANTI SCALD VALVES
APPLIANCE EFFICIENCY RATINGS
AQUASTAT CONTROL Functions
BACKDRAFTING HEATING EQUIPMENT
BACKFLOW PREVENTER VALVE, HEATING SYS
BACKFLOW PREVENTER, HEATER WATER FEEDER
BACKUP HEAT for HEAT PUMPS
CARBON MONOXIDE - CO
CHECK VALVES, WATER SUPPLY
CHEMICAL CONTAMINANTS in WATER
CHIMNEY INSPECTION DIAGNOSIS REPAIR
CLOGGED DRAIN DIAGNOSIS & REPAIR
CLOGGED SUPPLY PIPING
CROSS CONNECTIONS, PLUMBING
DEBRIS in WATER SUPPLY, Water Heater
DRAIN a WATER HEATER TANK
ELECTRIC WATER HEATERS
FLOODED HEATING EQUIPMENT REPAIR
FLOODED WATER HEATER REPAIR
FREEZE-PROOF A BUILDING
FROST HEAVES, FOUNDATION, SLAB
GALVANIC SCALE & METAL CORROSION
GAS BURNER Flame & Noise Defects
GAS FIRED WATER HEATERS
GAS PIPING, VALVES, CONTROLS
HEAT TAPES, Heat, Insulation prevent Freeze-Up
HEATING COST FUEL & BTU Cost Table
HEATING COST SAVINGS METHODS
HOT WATER SUPPLY
HOT WATER IMPROVEMENTS
HOT WATER DELIVERY SPEED UP
HOT WATER EFFICIENCY IMPROVEMENT
HOT WATER PRESSURE EXPANSION RATE
HOT WATER PRESSURE LOSS
HOT WATER PROBLEM DIAGNOSIS
HOT WATER QUANTITY IMPROVEMENT
HYDROGEN SULFIDE GAS
INDIRECT FIRED WATER HEATERS
MANUALS & PARTS GUIDES - HVAC
MIXING / ANTI-SCALD VALVES
NO HEAT - NO HOT WATER: HEATER DIAGNOSIS
NOISE / SOUND DIAGNOSIS & CURE
NOISE CONTROL for HEATING SYSTEMS
NOISE, PLUMBING CHECKLIST
NOISE, WATER HEATER
ODORS GASES SMELLS, DIAGNOSIS & CURE
ODORS IN WATER
PIPING IN buildings, Clogs Leaks Types
PLASTIC HEATER VENT
PLUMBING FIXTURES, KITCHEN, BATH
PLUMBING VENT DEFECTS & NOISES
PUMPS, HEAT PUMPS
PUMPS, OIL BURNER
PUMPS, PONY PUMPS
PUMPS, SEPTIC PUMPS
PUMPS, SEWAGE EJECTOR / GRINDER PUMPS
PUMPS, SUMP PUMPS
PUMPS, WATER PUMPS
PUMPS, WATER REPAIR
RELIEF VALVE LEAKS
RELIEF VALVES - TP Valves on Boilers
RELIEF VALVES - STEAM TP VALVES
RELIEF VALVES - Water Heaters
RELIEF VALVES - Water Tanks
SAFETY, HEATING INSPECTION
SCALE REMOVAL, WATER HEATERS
SEWER GAS ODORS
SOLAR HOT WATER HEATERS
SOOT on OIL FIRED HEATING EQUIPMENT
SPILL SWITCHES - Flue Gas Detection
TANKLESS WATER HEATERS
THERMOSTATS, HEATING / COOLING
THERMOSTATS, WATER HEATER
TIMERS for ELECTRIC WATER HEATERS
WATER CONTAMINANT LEVELS
WATER HAMMER NOISE DIAGNOSE & CURE
WATER HEATER ALTERNATIVES
WATER HEATER ANODES, DIP TUBES
WATER HEATER AIR INLET
WATER HEATER DEBRIS FLUSH
WATER HEATER DRAIN PROCEDURE
WATER HEATER EFFICIENCY
WATER HEATER FLUSH PROCEDURE
WATER HEATER NOISES
WATER HEATER PROBLEM DIAGNOSIS
WATER HEATER PROPERTIES
WATER HEATER SCALE - De-Liming Procedure
WATER HEATER SCALE PREVENTION
WATER HEATER SAFETY
WATER HEATERS for HOME HEATING USE?
WATER ODORS, CAUSE CURE
WATER PIPES, Clogs Leaks Types
WATER PRESSURE & FLOW MEASUREMENT
WATER PRESSURE GAUGE ACCURACY
WATER PRESSURE LOSS DIAGNOSIS & REPAIR
WATER PRESSURE REDUCER / REGULATOR
WATER PRESSURE PUMP REPAIR GUIDE
WATER PUMPS, TANKS, TESTS, WELLS, REPAIRS
WATER PUMP REPAIR GUIDE
WATER QUALITY TESTS, CONTAMINANTS, TREATMENT
WATER QUANTITY IMPROVEMENT
WATER SOFTENERS & CONDITIONERS
WINTERIZE A BUILDING
Repair leaky tankless coil on heating boiler: Here we explain Leaks at Tankless Coils on heating boilers: a guide diagnosis, evaluation, & repair of leaks at tankless coils. We introduce tankless coils as a source for domestic hot water, and we explain how they work at TANKLESS COILS. Here we explain leaks that occur at a tankless coil where it is mounted to the top or side of a heating boiler. Boiler leaks at a tankless coil mounting plate or at the pipe fittings that pass through the coil mounting plate are a common defect on heating boilers, both steel and cast iron units. Caught and repaired early, leaks at a tankless coil used to make hot water can be repaired without serious consequence. Left alone these same leaks can completely destroy the heating boiler. Deciding how badly a heating boiler has been damaged by leaks is tricky, controversial, and important since both safety and big cost concerns are involved.
Green links show where you are. © Copyright 2013 InspectAPedia.com, All Rights Reserved.
Leaks at tankless coils used to produce domestic hot water occur at the following locations:
A leak at any of these points will not normally show up as water on the boiler or on the floor around the boiler.
That's because the boiler is normally hot all of the time. Water leaking at any of these locations will rapidly evaporate.
What evidence of leaks will we observe at a boiler with leaks at the tankless coil?
White or other mineral salts left behind from evaporating leaky water, at and below the point of leakage, often staining the face of the boiler, such as we show in the photograph above. Even without close inspection one can observe white leak stains below the round black tankless coil plate and running down the face of the boiler in this installation.
A leak that has produced rust like this might mean that the tankless coil unit needs to be replaced, or worse, that the boiler has been so damaged by rust that it is beyond repair.
In the next section of this article we discuss how to evaluate leaks on heating boilers at a tankless coil
How to Evaluate a Leak at a Tankless Coil on a Heating Boiler
Young leaks at a tankless coil can be repaired
Which Tankless Coil Leaks & Boiler Leaks Can Be Repaired and When is the Boiler Ruined?
Rusty tankless coil face plate and boiler surface: Look closely at the coil mounting plate and the boiler mating surface to see just where the rust and exfoliating have occurred.
In our photo at left, this boiler, in Wappingers Falls, NY, was beyond repair. Leaks at the tankless coil had badly rusted the coil face plate, the boiler face, and even the boiler jacket.
In most cases a leak at the coil mounting plate, left unattended, will have badly rusted both surfaces and the boiler is likely to be beyond repair.
Rusty tankless coil face plate, possibly salvageable: But in some cases the rust and flaking may be occurring on the outer face of the tankless coil mounting plate, and there is a chance that the coil can be removed and replaced. In the photo above we show here we see severe flaking exfoliating rust on the outer face of the tankless coil face plate.
Frequently Asked Questions (FAQs) about leaks at tankless hot water coils: cause, diagnosis, repair advice
Question: can a leak be repaired with a tankless heater still attached to the wall?
can a leak normally be repaired with the unit still attached to the wall> Does one remove the pipes inside of the heat exchange of the tankless water heater? Are there parts for such items. My unit is Nakagki. Small water leak so far. - firstname.lastname@example.org 9/6/11
The type of tankless coil we discuss here is a part that inserts into a heating boiler; It can't be repaired if it's leaking, but the entire assembly can be replaced; It's a significant job - the boiler has to be drained;
Question: Home Depot "experts" said that repairing a tankless coil leak is impossible - but I used radiator heavy duty stop-leak from an auto parts store
went to home Depot asking if there is any way to fix my boiler coil’s water leak. They looked at me like an idiot. No way can you fix the coil, they said. You must change it.
Reply: Bad repair - you risk poisoning building occupants; don't try oatmeal in the tankless coil either.
Thanks for this interesting, if questionable repair idea for leaky tankless coils. It needs some clarification.
e are not sure what the effect may be on the heating boiler, circulator pumps, zone valves, relief valve, of the passage of any stop leak compound into those components through the leaky coil before the leak stops - those may be harmful. Auto radiator stop leak is not designed for this circumstance. It might work but it leaves me a little worried.
This leak, as you can see in our photos, destroys the boiler if it is not found soon enough, and destroys the tankless coil mounting plate - an integral part of the assembly. That's why the Home Depot rep was dead right when he said "replace the coil" - she or he was thinking of this common leak. Auto radiator "stop-leak" products won't fix this problem, and in fact running a stopleak product through the coil is irrelevant because that's not where the leak is found.
Questions & answers or comments about the cause & repair of leaks at tankless coils on boilers
Ask a Question or Enter Search Terms in the InspectApedia search box just below.
Technical Reviewers & References
Related Topics, found near the top of this page suggest articles closely related to this one.