New Heater Element Extremely Hot To Touch

[Doctorhawaii]

Hi.  Installed a new OEM Watkins 6Kw heater and sensors into a 2005 Vanguard about 4 months ago. Now, the high limit sensor trips every week or so, but resets fine. I have excellent circ pump flow through the water fall, and the ozone bubbles are plentiful. I installed 5 new Watkins filters a month ago. When the heater is on and functioning, the rear tube is EXTREMELY hot to the touch--as in it's too hot to touch--over about a 2-inch section of the tube.  So:  should that happen, or does that indicate this brand new heater element is bad? Or could it be the circ pump, even though it seems to be fine? Thanks.

[Doctorhawaii]

Anyone have any ideas?  Thanks.

[Spa Board Doctor]

Possible that the element in the tube is in very close proximity to the manifold in this area.  You can try to move the high limit to a cooler area on the manifold.  Low flow heater systems like this can be finicky.  When replacing the heaters on these, I typically use the 4.0kW version as they are less prone to overheat the barrel, even with partially restricted water flow i.e. dirty filters, debris in the circ pump impeller, clogged returns, etc. 

[Doctorhawaii]

Thanks for this...that sounds like what's going on, the element being close to the side of the barrel.  How would you move the high limit to a different place on the manifold?  And, with a 4 kW heater, would it adversely affect the heating? The tub is about 450 gallons.

[Spa Board Doctor]

Sorry, was thinking of a different heater, the high limit on your heater is fixed in position.

Whether you'd notice a difference in the heater wattage depends a lot on the climate in your area.  Warmer (non freezing) climates, probably wouldn't notice a difference.  Cooler (freezing) climates, might notice that the temp drops slowly while using the tub when it's really cold outside.

 

[Doctorhawaii]

Got it, thanks.  I spoke with Watkins, and one of their tech guys says the heater is flawed and should be replaced.  It's still under warranty so I'll just go ahead and get a new one and see if that solves the issue. Thanks again for weighing in...much appreciated!  BTW, I'll go ahead and put in a new circ pump while I'm at it, since the one I have is 20 years old and it's probably not a bad thing to update it.