I have had a few problems this year with my Hyrdotherm. 1st. The 1st floor zone called for heat all the time regardless if I took the thermostat off the wall. I had a bad zone valve. Had that replaced and cost me some change. Now the 1st zone is working properly. However, when it calls for heat, it also sends heat the the 2ns zone upstairs even though that thermostat is not calling for heat. So as a result. It is getting way too hot. The 2ns zone right now reads 78 on the thermostat and I have it set to kick on at 71. I replaced to bad bleeder valves although this problem existed before that. Basically, the colder it gets outside, the more the heat kicks on and the more heat goes to the 2nd zone when it is not demanding it. I had someone check the zone valve for free (same people that replaced the other zone valve) and it seemed to be ok. What else could it be?

Hydrotherm model HI-85B

Currently, the pressure on the unit reads 22psi.

Chris

 

Do you get heat on the 2nd floor when the first floor is satisfied? How do you supply your domestic HW is it a separate zone? Also what kind of zone valves do you have?
Geo

 

Hi Chris,

Can you take a series of clear well lighted photos of the system, all around, several angles, show us all the piping.

"Seemed to be" ? or WAS / IS OK ?

What is the make / model of the zone valves?

 

I will take somw pictures tomorrow and futher clarify. At work right now.

 

Here are the pictures you requested. I could not easily find the model number of the zone I am having problems with and it is in a very tight space in a closet. The other one you can read from the picture. They are both Honeywell.

Basement: (Zone B)
1st floor (Zone 1)
2nd floor (Zone 2)

I turned my boiler off this morning and let it cool down. Then I turned on the 2nd zone and it worked fine independently as I did not have any heat going to zones 1 and B. However, as stated before, when running zone 1, it sends heat to zone 2 despite there not being a demand for heat for zone 2. So in summary, Zone 2 works fine when I am only calling for heat for that zone and other zones are not effected. However, With zone 1 and zone 2 off but zone B circulating heat, zone 2 gets hot and zone 1 does not. So could there be a possibility of the zone valve getting stuck open or something else? I am a novice at DIY projects. especially plumbing. But I do understand enough to fix somethings with guidance. Any thoughts?

Thanks.

 

Is this something that just started happening?
Geo

 

Yes...Only in last 3-4 weeks.

 

Is that last picture you posted the valve for the second floor? Looks sorta corroded, etc...

When the thermostat is not calling for heat, and you move the auto/man lever, is the lever loose and floppy and moves side to side with no resistance? or does it have resistance and make the 'whirring' sound as the valve opens?

 

It does seem like the zone valve is hanging up,if you set all the Tstat's to 50 degrees the boiler should be off now, have someone turn the 2nd floor Tstat up to 80 degrees an observe what happens to that zone valve, you should hear the motor hum and then after maybe 2 or 3 minutes the boiler should start and water should start circulating to the 2nd floor only.
Geo

 

Moving the handle with no call for heat will tell you if the valve is stuck open.

If it moves freely, it's stuck open.

 

Thanks for the ideas. The funny thing is. After I turned it off for a day when the weather was mild, it is now working fine. So I will monitor the situation.