Hot water and Boiler temp

[Crumm]

Any boiler and hot water experts out there?

The hot water coil in my boiler plugged up recently and it seems as though when momma has to take a cold shower she ain't happy Today after trying to clean it out with acid for about two hours and not getting any flow I gave up and went and purchased a new one. After installing it I filled the boiler back up with glycol and for some reason the control panel decided to retire. I don't know if when I was purging the air out of the system that the circulating pump shorted it out or what but it quit. I installed a new and improved control and am back in business.

Now for the questions.

1. What is the proper setting for the high and low on the new control? I am currently running 150 on the low and 190 on the high. The old unit was set on about 160/200 but it didn't seem to work right as it was over 20 years old. When I set the new one on 160/200 the manual guage on the side of the boiler was about 10 degrees higher than it use to run.

2. What is the proper temp for hot water? I have a circulating pump that circulates water through the coil and into a storage tank. There is a thermostat in the storage tank that turns the pump on and off. The thermostat was set on 150 but with the boiler at 150 the pump seemed to run for a long time. I lowered the temp to 145 and it seems to shut off much sooner. Is 145 hot enough? I know there is a certain temp to kill bugs but I don't remember what it is. The thermostat is in the bottom of the tank so I imagine the water leaving the top of the tank is much warmer than 145 especially when the boiler kicks on.

If I raise the hot water temp I think I will need to raise the boiler temp some too. What do you think the temps should be?

 

[DaveBen]

My boiler/hydronic guy says to run at 150° every now and then. This kills the bugs, but you don't have to run it at 150° for everyday use. 145° is close enough to 150° that the bugs won't grow excessively. His recommendation was to run it higher every couple of weeks for a day and then go back to your normal setting. I personally know nothing about all of this.

Dave

 

[ktpauley]

I'm not a boiler tech, but I do regulate drinking water facilities. At 150 the only microbe that will live for a short time is Legionella. At a constant temp of 150 Legionella will die in 2 hours. At 120 to 140 Iron bacteria will flourish. Iron bacteria will cause a rotten egg smell. Sounds like ou might have hard water. Keith

 

[Crumm]

At 120 to 140 Iron bacteria will flourish. Iron bacteria will cause a rotten egg smell. Sounds like you might have hard water. Keith

Yes we have hard water. I don't like smelling rotten eggs so I am going back up to 150 on the water heater and 160 on the boiler.

 

[hheynow]

Yes we have hard water. I don't like smelling rotten eggs so I am going back up to 150 on the water heater and 160 on the boiler.

I'm no hot water heater expert either, but to keep the rotten egg smell down change the rod from zinc to magnesium (in addition to keeping it at 150*F).

 

[Crumm]

change the rod from zinc to magnesium.

What rod is that

 

[hheynow]

What rod is that

The anode

 

[Crumm]

The anode

Don't think I have one of those. My hot water tank is just a holding tank. Water is heated in the boiler.