beware of timers and boilers

[sixroses]

I have had 2 run ins with timers this year that have caused me a fair bit of trouble. The first was in early August. I was burning one fire a day at 4:00 pm. That would supply plenty of hot water for wife, 3 girls and laundry. I went caribou hunting with instructions to fill the greenwood with 6 pieces of birch, and then do the same the next day at the same time. Timer was controlling circ pumps. well...She was chilly so fired up a roaring fire early next day and poof melted solder joints and water on the floor...Just follow directions and all would be well. Second issue was last night. My new timer schedule of 1 hour on and 1 hour off through the night had been great untill the temps fell to -10 and sometime during one of the "off" segments I froze my lines coming to the house. I awoke at 5:00 am with a chilly nose and a bad feeling. After some scrambling and 2 space heaters, all is well and flowing again. Next venture will be to tie pumps into zone valves so pumps will run when zone calls for heat. During the cold nights there always seems to be a zone open every few minutes. Better pipe insulation would be a great help also.
Has heat tape on pex ever been discussed?

Stihl burning in Alaska,
Steve

 

[stee6043]

What kind of boiler do you have? I've never heard of someone running circ's with timers before. Sounds dangerous to me. Why not use an aquastat? When water is warm - pump runs. You could also buy a timer relay to give the pump a kick every few minutes when there is no heat to prevent freezing.

 

[ISeeDeadBTUs]

I am lost . . .

You put wood on once a day?
What is the timer controling?

You said the solder melted??? Taken from WIKI . . .
SnSb5, tin with 5% of antimony, is the US plumbing industry standard. Its melting point is 232-240 °C. It displays good resistance to thermal fatigue and good shear strength.

I need a map . . .

 

[sixroses]

Yes, melted solder joints. The timer was controlling the circ from the stove to the storage. Lots of heat, no place for it to go. The second instance was heat to house from storage in garage. I have eliminated the timers, to much potential for problems. -15 now so need to load up and head for bed.

Steve

 

[rkusek]

Since a circ takes between 60-80W (less than most light bulbs), there is absolutely no reason not to let them run 24/7, especially in Alaska. I would be worried about the same thing happening again if you sustained a power outage during the night. A UPC or battery/inverter would be a good thing to have to prevent another incident.

 

[ISeeDeadBTUs]

What were you trying to accomplish with timed circulation vs continuous?

I have contemplated varying the speed of circulation based on output temps and varying the sixe of the HX based on demand, but this turning OFF circulation . . . sorry, I'm not getting that hh:

 

[Tony H]

I have seen ad's for several heat tape types where they say safe for pex pipe

 

[rowerwet]

if you could melt solder with the heat, are you sure the boiler is ok otherwise?