Radiant system running even when indoor temp reached?

[Jotel me this]

Along with my wood stove, my house also has radiant heating in the floors (water) running off of a Navien-110 boiler. First test run for the winter season, the house temp started at 66 degrees today. After two hours it finally reached the set temperature of 68 but its still running and the digital display shows the little flame which means its still using propane.

Any ideas why?

 

[begreen]

Usually the thermostat has a swing setting to avoid short cycling. It may need to get .5-1º warmer before shutting off.

 

[OT_Ducati]

Along with my wood stove, my house also has radiant heating in the floors (water) running off of a Navien-110 boiler. First test run for the winter season, the house temp started at 66 degrees today. After two hours it finally reached the set temperature of 68 but its still running and the digital display shows the little flame which means its still using propane.

Any ideas why?

Does the t-stat have a floor sensor?

 

[fbelec]

not for a boiler. if it were electric yes. the boiler depending on the set up will only give the loop of heat 120 degree water. the thing with radiant is leave it at a set point and don't try using a set back thermostat or you will be left feeling cold and the heat bill with cost more

 

[Jotel me this]

Does the t-stat have a floor sensor?

nope.

 

[Jotel me this]

not for a boiler. if it were electric yes. the boiler depending on the set up will only give the loop of heat 120 degree water. the thing with radiant is leave it at a set point and don't try using a set back thermostat or you will be left feeling cold and the heat bill with cost more

what is a set back thermostat
the thermostat i have comes on a few times per hour even at temp for some reason

 

[begreen]

Has the thermostat swing range been checked? Is the boiler just for heating the floor or does it also heat domestic hot water?

 

[Highbeam]

what is a set back thermostat
the thermostat i have comes on a few times per hour even at temp for some reason

So the thermostat itself calls for heat even though it keeps displaying the set temp?

 

[fbelec]

what thermostat do you have? if it is the honeywell that senses wall and air temp that might be why it is coming on at random times. if it is the round type made by honeywell that is new (no mercury ball inside) junk it and get a different type those thermostats have a mind of their own and it's not a good one. if it is the old round honeywell that has the mercury ball those are the best. lasts for about 50 years. also if it's old check to see if it has a heat anticipater if so set it for 4

 

[begreen]

Could also be rounding of the display is not the same as internal temp reading so that 68.7 reads as 69, but the thermostat say, no that is not really 69 and turns on the heat until it is actually truly 69 or above. Just speculating here.

 

[Jotel me this]

So the thermostat itself calls for heat even though it keeps displaying the set temp?

what thermostat do you have? if it is the honeywell that senses wall and air temp that might be why it is coming on at random times. if it is the round type made by honeywell that is new (no mercury ball inside) junk it and get a different type those thermostats have a mind of their own and it's not a good one. if it is the old round honeywell that has the mercury ball those are the best. lasts for about 50 years. also if it's old check to see if it has a heat anticipater if so set it for 4

Could also be rounding of the display is not the same as internal temp reading so that 68.7 reads as 69, but the thermostat say, no that is not really 69 and turns on the heat until it is actually truly 69 or above. Just speculating here.

Thanks for all the responses. Great community



So, if the temp is set to 65, the heat will come on and run until 65. i think i didnt give it enough time to turn off as someone stated above, it might turn off .5 degrees higher to avoid short cycling.

once it turns off, even if the house is still 65, it comes on 2 to 3 times per hour. its one of the thermostats where you can press two buttons at once to get into the 'advanced settings'. one of the settings lets you choose the number of times it does this.. but there is no 'zero' setting.

took forever to find the instructions: (page 8-9)
https://customer.honeywell.com/resources/techlit/TechLitDocuments/69-0000s/69-1849.pdf

My settings (if it makes sense):

(first number corresponds to the options on Page 8 / Second number is your actual setting for that option)

1 0
5 5 <-------------- ? should i have this at '1'
9 3
13 0
14 0
15 5
70 Test

The setting in question is Number 5: Heating cycle rate (CPH: cycles/hour):

These are the options...

5 For gas or oil furnaces of less than 90% efficiency
1 For steam or gravity systems
3 For hot water systems & furnaces of over 90% efficiency
9 For electric furnaces [Other cycle rate options: 2, 4, 6, 7, 8, 10, 11 or 12 CPH]

..I have mine set to #5. But it allows me to choose Other cycle rate options. i can choose 1,2,3,4,5,6,7,8,9,10,11,or 12

should i just put it at 1 so that it cycles only one time per hour?? (if thats what this setting even means)

Sorry for the confusing post. looking at it in person its straightforward, but im sure its confusing for those looking at a jumbled mess of words and numbers

 

[begreen]

I would try it at 3 for a bit and see how that works out.

 

[fbelec]

sounds like it is trying to keep the boiler or furnace warm so when it calls for heat it can go right to work. my opinion is how ever many cycles it turns on for without it calling for heat it's wasting fuel. i'd set it for 1 so it's not coming on while you have the wood stove running

 

[Hogwildz]

If your hot water is also connected to the boiler, than it is going to continue to run as supply is needed.

 

[fbelec]

to add to hogwildz it will run on demand but also it will keep the water in the boiler at a set temp. and to add to that i've gone into homes where the hot water was moved out from the boiler tankless coil and to a tank and who ever did the move never took out the triple aquastat but turned it down to minimum temp which is around 100 so the boiler would hold that temp.

 

[CaptSpiff]

The setting in question is Number 5: Heating cycle rate (CPH: cycles/hour):

These are the options...
5 For gas or oil furnaces of less than 90% efficiency
1 For steam or gravity systems
3 For hot water systems & furnaces of over 90% efficiency
9 For electric furnaces [Other cycle rate options: 2, 4, 6, 7, 8, 10, 11 or 12 CPH]

..I have mine set to #5. But it allows me to choose Other cycle rate options. i can choose 1,2,3,4,5,6,7,8,9,10,11,or 12

I'm just doing a quick "drive by here" but isn't this the Maximum number of cycles per hour?

 

[fbelec]

best thing to do is call their tech support line they are usually good they should explain it.

 

[Jotel me this]

I'm just doing a quick "drive by here" but isn't this the Maximum number of cycles per hour?

yep. thats my question. should i lower the CPH? running on propane, its a killer to watch it run 3 times an hour when its already at temperature.

 

[begreen]

yep. thats my question. should i lower the CPH? running on propane, its a killer to watch it run 3 times an hour when its already at temperature.

How is your domestic hot water for showers heated? Same system or a completely different system?