Is Heat and Flush an Effective Legionella Treatment?
Heat and flush may not be successful as a Legionella treatment and may give only limited control over a short period. This technique, also referred to as superheating, has been regarded as a possible method of Legionella control in previous years. However, recent analysis suggests that its use should be limited. This is according to the New York State Department of Health in their publication, “Environmental Health Information Related to Legionellosis in Healthcare Facilities.”
Heat and flush (also referred to as super heat) for Legionella control consists of bringing hot water temperatures to 160°F and flushing each tap for a minimum 30 minutes. This is often not a useful approach for Legionella treatment because of the following factors:
- Many facilities cannot achieve these temperatures or exposure times making the method difficult to implement.
- Lower temperatures and shorter exposure times will be less effective.
- Care must be taken because the hot water may cause damage elastomeric gaskets and plastics that cannot tolerate higher temperatures. This may shorten the life of those components or result in component failure.
- Following heat and flush, there may be a rebound of Legionella colonization to higher numbers than originally detected.
Legionella testing should be conducted for some period of time following the heat and flush or superheating for the reasons above.
The failure of heat and flush protocols may require the use of other methods, so this should be considered upfront as part of a comprehensive Legionella control water management plan.
If you have tried heat and flush as a Legionella control treatment and found that it is not effective, contact our team at Legionella Control Systems so we can provide suggestions for more effective Legionella mitigation.
