[wwjj24]

Hi, my new place has a problem with holding hot water for any duration of time over 10 seconds. The sink in the kitchen, along with the bathroom sink seem to be in the same boat of having hot water and then going kind of warm and then cold or holding that kind of warm temperature for the rest of the time.

The shower is a completely different story though. I had some plumber come over to tell me to change the mixing valve (so I did). Before he left though he said there is a possibility of the switch valve (the think that prioritizes the shower giving hot water) being broken. In time I found out the hot water pretty nonexistent when I try to turn it on; as it would get to a hot point then drop pretty quickly to freezing cold and continued like that until I turn it off.

The funny thing is the thermostat when turn up to a higher than the temperature it reads; activates hot water for at a long enough time for a shower (as long as the raised temperature isn't change immediately afterwards). There also a thing with the boiler activating and make a whistling noise (for a few seconds) and then it goes away every few hours I’d say.

The problem with doing this often it seems the temperature it reads keeps going up and won't go down, even when I turn the heat temperature down 20 degrees. I was wondering if the cool option (last pic) would be best to turn it down or pressing the reset button on my boiler (or the thermostat)? Or is the plumber right in the switch valve being broken?

Thank you to anyone that reads the wall of text and any information would be helpful for my next step.

P.S

http://imgur.com/a/0T0tX

The album pics description in order (sorry about the order of the pics)
1. boiler(old Laars model)
2. behind the thermostat
3. thermostat wiring
4. thermostat wiring(side view)
5. switch valve(broken?)
6. thermostat(front view)

[massplumber2008]

Hi Wwjj24

With this style boiler system you will be best off to call the manufacturer directly and talk to the tech. support department. Here, we could all spend hours typing/waiting and trying to troubleshoot this thing and still not come up with the correct answer... ;)

Contact tech. support and have an electrical tester handy as well as the model and serial number of the boiler unit. They should figure this out fast!

Here is a direct link to LAARS: Laars Heating Systems: High Efficiency Residential and Commercial Boilers, Combi Boilers, Water Heaters and Pool Heaters | SUPPORT

Good luck!

Mark