Furnace fan speed issue

[kafansler]

I have a Bryant Plus 80V furnace (model # 315AAV0). I am having an issue with getting the fan go to high speed when using the Continous Fan mode. I have the dip switches set to have it run on the highest setting and it still only spins at the lowest speed. Also about every few days the 3 amp fuse on the control board blows!

Here is a brief discription of what I am doing. In the winter I use an outside wood "water" furnace to heat water and then run it through a radiator which is mounted just above the A coil in the furnace. I turn down the house thermostat (the one installed with the house furnace system) and use an additional t-stat for the water system. I then tied into the G and 24 V com terminal on the control board of the furnace. Using this system worked all last winter flawlessly and up until about one month ago. I was working on the outside wood furnace so I switched the t-stat to off while the water temp would be cool. Then in a few hours I turned it back on the blower fan was running only in low, and it has been this way ever since. If I run the furnace/heat pump the fan goes to high as designed?????? Any help would be great. Is it a control board??????

Thanks

[paul52446m]

I have a Bryant Plus 80V furnace (model # 315AAV0). I am having an issue with getting the fan go to high speed when using the Continous Fan mode. I have the dip switches set to have it run on the highest setting and it still only spins at the lowest speed. Also about every few days the 3 amp fuse on the control board blows!

Here is a brief discription of what I am doing. In the winter I use an outside wood "water" furnace to heat water and then run it through a radiator which is mounted just above the A coil in the furnace. I turn down the house thermostat (the one installed with the house furnace system) and use an additional t-stat for the water system. I then tied into the G and 24 V com terminal on the control board of the furnace. Using this system worked all last winter flawlessly and up until about one month ago. I was working on the outside wood furnace so I switched the t-stat to off while the water temp would be cool. Then in a few hours I turned it back on the blower fan was running only in low, and it has been this way ever since. If I run the furnace/heat pump the fan goes to high as designed?????? Any help would be great. Is it a control board??????

Thanks

What are you turning on with the wood stat?
Tell me how many wires are on the furnace stat and what post they are on at both the stat and furnace. Also tell me how many wires on the wood stat and what post they are on at both stat and furnace? Later paul

[kafansler]

Paul,

Thanks for the reply. First with the wood stat, I am turning on the blower on the house furnace to blow across the radiator. The wood stat is a simple two wire RH and W that then goes to a Tyco zone controller where it then sends a 24VAC out to (1) a zone valve (this allows the water to flow to the radiator) and (2) the control board on the furnace where they hook to G and Com 24V.

Sorry this is so confusing. The furnace stat goes thru a bryant zone controller then to the furnace. I can get those landings if still needed. I have the furnace stat turned down to 58* so it never calls for heat. I just need to have the blower on the house furnace come on when the wood stat calls for heat, and never blow the fuse!

Thanks

[paul52446m]

Paul,

Thanks for the reply. First with the wood stat, I am turning on the blower on the house furnace to blow across the radiator. The wood stat is a simple two wire RH and W that then goes to a Tyco zone controller where it then sends a 24VAC out to (1) a zone valve (this allows the water to flow to the radiator) and (2) the control board on the furnace where they hook to G and Com 24V.

Sorry this is so confusing. The furnace stat goes thru a bryant zone controller then to the furnace. I can get those landings if still needed. I have the furnace stat turned down to 58* so it never calls for heat. I just need to have the blower on the house furnace come on when the wood stat calls for heat, and never blow the fuse!

Thanks

I would have to see all your wiring diagrams before a could have a chance of trouble shooting. Most electronic boards in furnaces, the fuse is just big enough the run the controls of the furnace, maybe 3 amps.
is this zone control coming off the same 24 volts from the furnace? Is the water zone valve also coming off the 24 volts from the furnace?
Paul

[kafansler]

The zone controller has its own 24v transformer. Basically I am "tricking" the blower on the house furnace to get it to come on. So the house furnace is not being added to I don't think. Remember I also suddenly had the fan stop running at the higher rpm setting as the dip switches are set to. I have tried to change the dip switches and no change. I will try and get a few drawings posted today of the entire system.

Thanks
Kyle