Solo 60 no heat ????

[webie]

This is my seventh year of burning with this system and for some odd reason I am starting to have a weird problem that I have never had before . What is happening is for some odd reason during the middle of a burn cycle if I have several zones call for heat at nearly the same time the water returning back to the boiler is cold enough to cause the termovar valve to close . stopping all heat from going to the zones . I have waken up several mornings to a house that is in the low 60's . The boiler is still mostly full of wood and up to temp .
My biggest question here is has anyone ever had a termovar valve fail at all ? My return water after the valve normally runs between 154 and 160 , every time that I have had this heat problem I am usually over 160 for the return mix temp and my return zone temp is way low like usually under 100 .
I am getting some heat to the first parts of my zones but the heat is dissipated by the time it returns to the boiler .
Some of you may think I am a little nuts here but I think my wood may be too dry .
Before the start of the burning season this year I changed out my smoke pipe as it was all rotted out , this time when I replaced it I did not replace the barometric damper . My wood for the most part has been dried inside for the better part of a year after 1-2 years of outside drying .
What I have been observing is I am continuing a small gasification burn after the blower is shutting down , I am also observing the damper on the blower dancing a bit so I know its sucking air in , I believe this is creating just enough heat to the boiler so as the combustion fan does not call for heat yet its not enough hot water to push through the zones to return back to the boiler to remix .
This weekend I installed a barometric draft back in the system again hoping this takes care of it , The small gasification burn has quit for now it seems to be working .
Has anyone else had this no heat problem with a hot boiler ,has anyone had a termovar valve fail and can you replace the insides ? Is it possible for my taco pump to be getting weak ? or ?????
I can get heat to move by turning up the fan heat setting increasing the boiler temperature but I usually turn that back down so as not to over heat my storage which is 1200 gallons and will go up to maxes out at 170-175
I am just baffled over this
Any answers guesses or what ever let me know I am baffled and been playing with this for 2 months now in fact I found this sight trying to search for the termovar valve .
Just a bit of added information the combustion blower kicks on at about 82 c I believe that to be about 179 f degrees.
The only other thing I can think of is trying to change the amount of hot mix water returning to the termovar valve from the hot supply by changing the ballcock valve which is set at about half .
Does anyone know what to expect if I decrease or if I increase this flow-age? It doesnt seem to me to change much of anything other than turn oof the hot supply .
Thanks
Steve

 

[Tarmsolo60]

I would think it would always happen if the circulator was a possible problem, My thought is your termovar is sticking and not sending heat to the loads. the heat is leaving the boiler and returning immediatley because of it.

 

[jebatty]

One or more airlocks also could be the problem. Bleed the system.
Shut down all zones, and one by one test each zone to see if heat is reaching the zone. Bleed air from each zone as needed.

Your burning, whether or not extra dry wood, and without the barometric damper, sounds perfectly normal to me and pretty much exactly what I get on an idle. When the draft fan shuts down, some chimney draft continues, a light gasification burn continues, but the stack continues to cool, burn stops, and stack ends up at about 100 until the draft fan kicks back on. My boiler output max is about 190-195F on draft fan shutdown, and then cools as heat is demanded from the boiler, draft fan kicks back on at about 180, but boiler cools to about 170-175 before the resumed burn starts raising the temp again.

 

[webie]

I purged the system yesterday , There was no air to be found at all . The problem is intermitant and seems to happen mostly at night and when it is colder . I myself am thinking that the termovar maybe sticking , does anyone on here no much about there operation ?

 

[wedgeeater]

The "guts" of the termovar can be replaced very easily. If you have the newer style with the ball valves on the unions, it is easy as pie. If not you'll need to drain, cut out the termovar, and repalace the "guts". I'd say if your cutting into the piping, get the new style termovar that has the valves for future ease. Definitely seen termovars stop functioning. I assume you've had the supply bypass path (which cuts in more hot water as needed) half-cocked since this is the first trouble you've had in a long time. If that path was stuck open (failed termovar guts) it would continually bleed hot water off the supply, giving you warm return temps, but less heat in your distribution. Good Luck!

 

[hoth2oguy]

Hi webie, if you can isolate the Termovar, it is easy to remove the guts of the valve. This is a cage and thermostatic actuator and is accessible behind the aluminum plate with the red arrow on it. Remove the two bolts holding the aluminum plate on and you will see four brass screws. Remove these screws and the side plate comes off so you can pull the thermostat. If you remove this and the situation improves, a replacement element can be ordered directly from us (call Brian in parts).

If removing the thermostat does not solve the problem, I would look to a failing or failed pump.

Chris

 

[webie]

Thanks guys for all the input . I can isolate somewhat the termovar although I will still need to completely shut down the heating system includeing back up LP . Also on my end it will be a little messy I will be draining aproximately 5ft of 1 1/4 pipeing and I am useing antifreeze in my system .....No big deal . Due to the above situation I will put the removal of the termovar thermostat till the end of the heating system . I am almost positive this has to be the problem that it is sticking .
Since I first posted and putting in the barometric Draft in I have yet to have it fail and I even tryed last night by dumping 3 cold zones to the boiler at one time , It took about 10 minutes and all the cold water purged through the boiler and the system kept right on running . Like I said in the beginning it has been very intermitant.
I will call Brian at Bio and see about getting the guts for the termovar and just replace it .
Thanks
Steve