Concealed Radiant Panel Leaks

The hydronics industry is sometimes plagued by inexperienced, incompetent, and improperly licensed Contractors who claim to understand how to locate and repair concealed radiant panel leaks. This results in homeowners believing their systems were properly repaired when in fact only part of the work was completed. For a radiant panel system to operate efficiently, it must be “leak free” and closed. A discussion follows which will help the homeowner understand this condition and how it can easily be corrected. 

There is confusion about the cost to repair concealed radiant panel leaks in the Eichler and Custom Home. Being in the hydronics business for 54 years, we know homeowners and insurance companies are paying thousands of unnecessary dollars to perform these repairs. Day after day, we hear horror stories describing leak detection and digging procedures which are damaging homes and serve only to “make” work for the inexperienced Contractor. ANDERSON RADIANT HEATING is committed to providing accurate information regarding the location and repair of hydronic leaks. By understanding and implementing the following guidelines, you can protect yourself from making an improper and disastrous decision regarding the repair. Since the hydronics industry is traditionally a narrowly specialized field of work, it suffers from not having enough competent, experienced and knowledgeable contracting personnel. From 1950-1965, when the Eichler Home was constructed, there were only five companies who specialized in the design, installation and repairing of the hydronic radiant heat system. We are considered by our clients and customers to be the only qualified company in our area to perform this service. Plumbing and Heating Contractors have generally left this specialty to Hydronic Heating and Boiler Contractors (Classification C-4) because of the complexity of the work. The California State License Board has identified the C-4 specialty as a proper license classification to perform leak location and repair on radiant panel systems. When a leak occurs in the concealed tubing of the radiant panel, all copper tube systems are repairable. Because of the “closed-loop” environment there is absolutely no electrolytic degradation of the copper tubing. The reason for leakage in a copper radiant panel system is excessive stress. As all concrete slabs crack, if the tube crosses the crack and enough stress or movement is placed on it, over time the tube will anneal and split. The Eichler tract homes were built with thinner and non-uniform slabs which have been subjected to more movement, settling, and cracking than the custom slab home. Usually, the copper radiant panel homes we repair today have an average 1-5 leaks which have developed during the last 30-50 years of continued grade stress. Because of many years of experience and new leak detection techniques, we believe that once we perform a leak detection, location, and repair of these homes, they will be trouble-free for many years to come. 

Steel tube radiant panel systems are NOT REPAIRABLE because once they begin leaking, it is an actual degradation and deterioration problem which can only aggravate more problems by attempting to fix it. These systems must be replaced with another heating system. On occasion, a special type of sealer may be added to help prolong the steel tube systems life. This is not to say all steel systems are leaking because if they were installed at the proper height in the concrete and the protective plastic coating was undamaged during the concrete pour, they can last many years. It is the steel tube systems which were pushed below the bottom of the slab and subjected to degradation from external environmental factors that have failed. Hydronic baseboard is the most common choice for replacement of the heating system in the Eichler Home. Before contracting to locate the repair of any leak, the following guidelines should be considered:

  1. Have a hydrostatic pressure test performed prior to commencing the work. This simple test will confirm the presence of one or more leaks in the concealed tubing. IT DOES NOT DETERMINE HOW MANY LEAKS ARE IN THE SYSTEM. Ensure the person performing the test shows you the pressure drop and explains the amount of water lost from the system. A DROP IN THE SYSTEM PRESSURE IS SYNONYMOUS WITH A WATER LOSS IN THE TUBING CAUSED BY ONE OR MORE LEAKS. Because the radiant heat system is a “closed-loop”, any water loss is replaced by the automatic fill system at the boiler. This constant replenishing of the water with “new city water” will destroy the heating system and its support equipment because of rusting and corrosion. THERE ARE NO SMALL LEAKS IN THE CONCEALED TUBING SYSTEM. The hydronic radiant panel contains 5-20 gallons of water. The smallest of leaks result in the replacement of the system water within a few hours or days. ALL THE LEAKS MUST BE LOCATED AND REPAIRED IF THE SYSTEM IS TO REMAIN EFFICIENT, OPERATIONAL, AND TROUBLE-FREE.
  2. The newest, safest and ONLY reliable technique to locate concealed radiant panel leaks is “HELIUM SPECTROGRAPHIC ANALYSIS”. This technique uses a spectrograph that “sniffs” the presence of helium molecules. An appropriate spectrograph will cost in excess of $25,000.00. We know and understand the importance of proper leak detection, which is why we invested in the purchase of a spectrograph — our competition does not, thus they cannot accurately detect leaks. Do not be fooled by Contractors just saying they use helium detection. True helium detection employs a spectrograph with a sensitivity factor of one part per billion. Only with this sensitivity can the operator be assured of locating the smallest leaks. This method is far superior to any other technique because of the following:
    1. Helium gas is injected into the concealed tubing system at very low pressure, approximately 10-25 PSI. All other methods require high pressures, approximately 80-150 PSI.
    2. There is never a requirement to remove furniture, carpeting, padding, other floor materials or water beds to locate any leak.
    3. Because the Helium Spectrograph “sniffs” the helium molecule concentration at the point of the leak, there is NEVER A REQUIREMENT TO DIVIDE THE ROOM AREAS INTO QUADRANTS, PERFORM EXPLORATORY DIGGING OR REPLACE EXISTING DISTRIBUTION MANIFOLDS.
    4. The size of the helium molecule allows it to penetrate the smallest of openings. The miraculous results are 100% success rate in locating all the leaks, both large and small. In fact, the experienced operator has the additional ability to locate hair-line stresses in tubes which may leak helium and not water. This means all the problem stress areas are located thus eliminating the need to return for future repairs.
    5. An experienced leak crew of two persons can complete most leak repairs within one working day. It does not matter if the home has one or five leaking tubes. It is the exception to carry over a leak detection and repair for a second or third day.
    6. All repairs of the leaking tubes must be done in accordance with the UNIVERSAL PLUMBING AND MECHANICAL CODES. These universally accepted procedures are required by State and Local Agencies and ensure a proper repair. These procedures require all the joints to be silver-brazed for strength. All pressure testing of the radiant panel system should comply with ASME BOILER AND PRESSURE VESSEL CODES AND PROCEDURES OR THE UNIFORM MECHANICAL CODE.
  3. Penetration of the slab to expose the leaking tube is accomplished with a small 30 lb. electric jackhammer. Most of the dust and dirt are removed from the room with a large vacuum cleaner. Penetration of the slab should be accomplished only at the “LEAKING TUBE”, our competition is often guilty of “exploratory digging” — which no homeowner should ever be comfortable with.
  4. For insurance purposes only, the invoice for all the work is required to be divided into plumbing and non-plumbing work. The plumbing items include the labor and materials to actually repair the burst copper tee or tube once it has been exposed. The non-plumbing items include the labor and materials for all other work:
    • location of the leak
    • digging into the concrete to expose the leak
    • replacement of damaged boiler items caused by the leak (some insurance companies only)
    • replacement of tile, linoleum, carpet, padding, wooden and other floor materials
    The insurance company may reimburse the homeowner for approximately 90% of the total invoice as non-plumbing work. It is the Owner’s responsibility to pay for the plumbing items, approximately 10% of the total invoice, plus the insurance policy’s deductible. PROTECT YOURSELF!! ALWAYS CHECK WITH YOUR INSURANCE COMPANY BEFORE BEGINNING ANY WORK FOR THE EXACT COVERAGE ALLOWED BY YOUR POLICY.
  5. Hire a Contractor who works for the Owner of the property and not the insurance company. BY LAW THE OWNER MAY CHOOSE ANY CONTRACTOR TO PERFORM THE WORK.The insurance company may recommend a Contractor to perform the work who is inexperienced in hopes to save on the cost of the claim. Ensure you are completely satisfied with any recommendations and check references of recent jobs performed.
  6. Have the Contractor present all leaking tubes to you for inspection. If he fails to show you the leaking tube, probably no repair was made. Keep these tubes for examination by the insurance claims representative when requested.
  7. After the repair has been completed another pressure test is performed to verify there are no more leaks. This test should be accomplished with the boiler removed or isolated from the system and the air expansion tank removed. A proper code approved test for copper tube systems would be a 45-100 PSI for 45 minutes. There should be “NO LOSS IN THE PRESSURE”. Confirm this test by observing the starting and ending pressure displayed on the test gauge. A proper test gauge for performing this test is one with marked degradation’s of 1 PSI or less.
  8. THE COST TO PERFORM A COMPLETE LEAK REPAIR ON A RESIDENCE SHOULD NEVER EXCEED $7,500.00. THE AVERAGE COST TO COMPLETELY REPAIR MOST EICHLER HOMES IS APPROXIMATELY $1,250.00 – $2,500.00. This cost is slightly higher for large custom homes.

Radiant System Operation with Leaks The most common question asked about hydronic radiant heat is “CAN A HYDRONIC HEATING SYSTEM HEAT A RESIDENCE WHILE CONTAINING LEAKS?” The answer is “YES”. Often we perform a hydrostatic pressure test for a maintenance check or home sale and detect leaks when the owner insists the system was heating the home. The radiant heating system is a “closed-loop” system never requiring the addition of new water. As long as the automatic fill system continually maintains the system pressure by adding new water to the system created by leaks, it will appear to heat the home but the actual operation is inefficient and destructive to the boiler and support equipment. ALL LEAKS, BOTH LARGE AND SMALL, MUST BE LOCATED AND REPAIRED FOR PROPER SYSTEM OPERATION. Approximately 90% of all the leaks in the concealed tubing will NEVER BE VISIBLE for “slab on grade” homes. The water loss occurs downward into the grade while not leaking into the home. The advent of new flooring materials often will provide a seal at the point of leakage. HOW IS THE HOMEOWNER TO DETERMINE OR SUSPECT A LEAK MIGHT BE PRESENT IN THE RADIANT SYSTEM? The only positive means is to perform a hydrostatic pressure test on a regular basis. Perform a pressure test every two years or whenever the home is sold. Also, perform a pressure test when a serviceperson suspects there is a leak in the concealed tubing, when you remodel the property or replace any floor coverings, or where any slab penetration is required, for example, drilling for termites and/or injection of pesticides. Other indications of a possible leaking system include the following:

  • visible water on the floor
  • wet carpeting or padding
  • staining of the carpet
  • discoloration of the grout between ceramic tiles
  • warpage of wooden floor materials
  • insufficient heating in one or more rooms of the home
  • reading a pressure loss on the system gauge (normal pressure is 10-25 PSI)

The introduction of “new city water” into the system caused by leaks will damage and destroy the boiler and its support equipment. The continuous refilling of any radiant heating system with oxygenated water corrodes and rusts system components because they are manufactured with iron materials. When the automatic fill system fails completely, the boiler can continue to operate with little or no water. This results in heat exchanger and coil damage from overheating. Overheating is a fire hazard. With boiler systems costing $6,500.00 or more and support equipment costs rising the wise homeowner will monitor their system weekly during the heating season and monthly during the non-heating season. THE PERFORMANCE OF A HYDROSTATIC PRESSURE TEST ON A REGULAR BASIS OR AS OUTLINED ABOVE, IS THE SUREST WAY OF PREVENTING SYSTEM DAMAGE AND UNNECESSARY EXPENDITURES FOR REPAIRS. It is important to realize any hydronic system is constantly under pressure even when the system is not operating. The system pressure should be maintained at 10-25 PSI at all times. This means water loss due to leaks will occur ALL YEAR LONG. Because the volume of water loss can be more or less than 1-5 gallons per month, monitoring the water meter or water bill will not detect a system failure. 

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