Thermal By-Pass Valve

I love my Watts hot water circulation system which uses one of these valves under the sink in the farthest position of my plumbing. Unfortunately, these valves are the weak link in the system, as they are prone to sticking closed and/or clogging up. There is no substitute or work around for the valve so if you like your system, you must use this valve. No matter what the brand name, all valves (and circulator pumps) are made by Gundfos (sp?) who holds the patents on both devices. So, once per year or so, I replace it! I got the last one from Supply House.com and they were great! the 1st one I received from the would stick closed until being tapped - NO FAULT OF Supply House.com. Upon contacting them, they CHEERFULLY sent another one that day no charge for part or shipping! Once I received it and replace the bad valve, I returned the bad one using the provided return shipping label, again, NO SHIPPING COST to me. WOW! This was so great since to remove the valve and return it first, I would have to re-plumb the sink using different hoses, until the replacement arrived. I will use Supply House.com for ALL future plumbing supplies...

The design of this valve has poor reliability. I have had to replace mine more than 3 times in two years. The valve either sticks open or closed When it is stuck closed it acts like it was never installed. When it is stuck open, it pumps hot water all through your cold water system. I discovered it when I watered the garden and the hot water came out of my garden hose! This manufacturer charges a LOT of money for a simple plastic part and they have no competition so no incentive to improve quality. Try another approach to circulate hot water. This is a well documented failure and you will likely get caught in the trap. If you install one and it fails. You will not be able to take yours out and send it back unless you have the plumbing lines available to return the system to the original form.