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[Ridge]

I am not sure about my temps, stat is set at 180 ( doesn't go higher than that?) High limit 200 however the temp gauge on front never goes above 170 and kicks on at 152-3 I have checked lines leaving stove with temp gun and that says same temp and when checking lines after 40 plate exchanger it matches temp gauge on house boiler. The stat has a stop on it at 180 which seems like 170, does this seem normal?

[hondaracer2oo4]

Aquastat probably isnt accurate. I put a Ranco on this year replacing my old Honeywell mechanical aquastat. For the most part the honeywell was accurate but once in a while it would stick or not work appropriate.  I would look into getting a Ranco or Johnson controls. They are about 50 bucks. Approximately half of the cost of a mechanical aquastat.

[heat550]

I am not sure about my temps, stat is set at 180 ( doesn't go higher than that?) High limit 200 however the temp gauge on front never goes above 170 and kicks on at 152-3 I have checked lines leaving stove with temp gun and that says same temp and when checking lines after 40 plate exchanger it matches temp gauge on house boiler. The stat has a stop on it at 180 which seems like 170, does this seem normal?

I replace mine years ago with mine as it on top of door in front it got quite dirty
And it did same as yours. I put a new one in and covered it with aluminum foil . worked
Over 10 years now. Knock on wood.


Heat550

[kso5002]

I too have this issue. Brand new stove, started it up less than a month ago. This morning my temp was down to 150 but my aquastat is set to 180 with a 5 degree differential. Its maddening.

[tinfoilhat2020]

i was havint these same issues....here are my findings: my high limit was also set at 180 (factory set and couldnt b set higher) when the aquastat shut the lines down the temp gauge on the front of the boiler and my in line temp gauges elaving the boiler all read 170. After thinking it over and speaking with Mike at heatmor, he agreed that it sounded like the aquastat was reading off of ambien temperature (the temp of the air in the rear panel ). it does get mighty hot in there...expecially when the stove is calling for heat. So i tried a few different things, i first hook up a similar honey mechanical stat that had a high limit of up to 240....i messed with the setting a bit until i got a 180 reading on the boiler temp gauge and the line temp gauge.....i had my aquastat set at 190 with a 5 degree diff to acheive 170-180 real temps. I also wired up a Ranco aqustat and that got me even closer....i had the ranco set at 183 with a 10 degree diff to achieve the real temps of 170-180. Hope this helps someone

[slimjim]

Are you guys perhaps not getting enough flow through your boilers and the water not mixing properly, I have seen this happen, especially with the newer, more efficient units, remember, the top of the boiler with not so good flow will always read higher on the Aqua Stat as that is where the sensor is! Tricking the boiler by adjusting the Aqua Stat higher could put your boiler in danger of overheating quicker.

[tinfoilhat2020]

slim, i questioned the same thing....but i also tested the delta temps on both lines and everything is good.....flow at the house and shop is good....any thoughts??

[mlappin]

slim, i questioned the same thing....but i also tested the delta temps on both lines and everything is good.....flow at the house and shop is good....any thoughts??

What is the flow number though?

Heatmaster is quite specific for minimum amount of flow to ensure good mixing and to prevent any water from boiling in their G series.


From the G series owners manual.


Because of the efficiency in which your G Series furnace transfers heat into the water, it is important that enough water flow is present in the system. If there is not enough water flow, the water around the heat exchange tubes may boil while water in other parts of the tank are cool. It may be necessary to install a mixing pump on an unused set of lines to make sure there is enough flow in the furnace to keep this from happening.
The following are required flow rates:
G100 – 8 GPM (one typical building circuit)
G200 – 16 GPM (two typical building circuits or one building circuit and a mixing pump on the back of the furnace)
G400 – 25 GPM (four typical building circuits. If less than four, a mixing pump should be installed at the back of the furnace)
A typical building circuit would provide 6 – 8 GPM

[tinfoilhat2020]

thanks for sharing that....i have two pumps hooked up...ill have to add up the flow

[mlappin]

I’d like to here from others about flow when using Delta T pumps, I have a Taco I’m using now, but I have it set for the faster minimum flow, wonder if that would cause a problem on some of these gasifiers that need higher flow?

[tinfoilhat2020]

I have a B&G NRF 36 on the 2nd speed and a B&G NRF 22 for the shop loop

[mlappin]

I have a B&G NRF 36 on the 2nd speed and a B&G NRF 22 for the shop loop

Does Heatmor say anything in their install manual about a minimum flow?

Kinda a crude way to do it, but when checking thermostats for engines I place em in a pan of water on the stove and place a good candy thermometer in it to compare temps. I think I read somewhere though you’ll have to drain some water in order to remove your aqua stat?

[tinfoilhat2020]

no, the aquastat is in a well...the high limit switch is actually plumbed right into the way.

I have compared temps on the aquastat to the line temp gauge i have coming out of the boiler on the suplly line....when the aqaustat shuts off at 180, the suppy line temp gauge and the temp gauge on the front of the boiler both read a hair over 170. But you make a good point, i guess it could be flow within the boiler. Heatmor has no recommendations in their manual as to the amount of flow needed

[tinfoilhat2020]

here is a pic of how my pumps are set up...the supply and return ports are 1 1/2 inches....i would think there would be plenty of flow

[heat550]

here is a pic of how my pumps are set up...the supply and return ports are 1 1/2 inches....i would think there would be plenty of flow

Aqua stats heres my findings the new 400 acts just like my 200 . theres about 6-8 degress cooler at bottom of tank then what the gauge and aquastates say .  Front gauge and aquastats are right on because there same hieght in tank. because the supply lines at bottom of tank its never going to be same temp at bottom as it is at top .  I set the aquastat at 150 and if you watch the front temp gauge fans shut off right at 150f fans turn on right at 135f  I have 15 degree dif.  Im still testing mine will end up at 180f but I bet it be about 172f out the bottom of tank . I would have to set at 190f to get 180f out the bottom of tank . I have 30 gpm flow right now
3  -1 inch lines going in to 1 1/2 tees .  But you know 140f air exchanger puts out some serious heat .  even at 140f 1 air ex changers heating a 28x48 feet house no basement to 75 f

Heres a air ex changer example  right now theres 3 air exchangers in my system there heating  3504 sqare feet no fans are running . its 36 f outside  each exchanger average output is 60,000 btus  So if all fans were on it pull 180,000 btus  I only have baseboards in the biggest house and thats another 2500 square feet . it can only pull 35,000 btus  So full pull on the 400 is T 215,000btus .  that be half what stove can do .  Some times I think its fine tuning of air exchangers and fans that make system work right . Bigger and smaller fans make the boiler act totally different .  I have a 1600 cfm fan I put on a 140,000 air exchanger once its like the fan on exchanger kick in and 15 mins later stove would be going wild . It was just way to much made for nice warm shop though .  yes that fans still on a shelf now as its just to dam big . Went back to a 700cfm fan its more then enough .


Heat550