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Legionella Prevention Action Plan???
So I convince this hospital that changing their HW system from steam indirect coil to condensing HW heaters would save money in operation and up grade their 1970's method/equipment. Part of this was me voicing a concern of Legionella possible in their 360 gallon 40 year old tank that was kept at a lukewarm 120 degrees. The Legionella concern was considered oh-hum...maybe.
So I change out the system to 2 HTP condensing water heaters.
One month later they tell me that there now must be a Legionella prevention plan in place.......(also jokingly accuse me of instigating this requirement).
Just changed out a WH for a nursing home and they too must have a plan. HTP Phoenix installed as for the hospital.
So for the hospital and the nursing home we have a tank heated up to 140/145 with temp valve set at 120.
Sounds good so far, the return is about 115. Recirc pumps run almost continually.
The logic is that the return water is sent back into the 140 tank to be cooked. The reality is that most of that water is sent thru the mixing/temp valve with a little 140 added to make the trip again at 120.
The faucet temp at the end of the circuit might be only 115-118.
The temp for the tub is again tempered down to 108-110.
Attached is a plan for prevention, does it seem to make sense?
I was surprised about the ice machine, but did read about this being a cause.