Boiler/thermostat issue

landryB

**Additional info at bottom.
Just recently moved into a new house that has a boiler system for heat. The house is a main floor and a basement, each with their own zone control/thermostat. I’ve set the basement temp to 65 and the upstairs to its lowest setting (55). For some reason upstairs consistently gets to 80 degrees and rising. I then turn the boiler off and within the day it the temp drops I then reset the process every other day depending on outside temp.

The thermostat upstairs will correctly track the current temp but will still circulate hot water consistently increasing the heat. The thermostat downstairs tracks as well but won’t run as often as upstairs pump. Each day I run the boiler change something in the house to prevent the heat from rising upstairs, like closing ceiling ac vent, basement door, etc.

I just had the system serviced and they put in a new Pressure reducing value, new Pump for the downstairs, new Expansion tank, and new pressure relief value. Besides those replacement they said the system was old but still functional with no issues.

Any ideas what the issue is?

The new circulator is a B&G NRF-25. The older Circulator is a B&G SLC-30.

EBEBRATT-Ed

You either need check valves in the circulators (which you may have) or flow check valves which you don't have. It also looks like you had zone valves at one time, and the actuators are removed.

mattmia2

The circulators need to have flow checks in them, maybe the circulator that was replaced does not have a flow check, or the new circulator is big enough to open the flow check in the other circulator. my bet is on them replacing a circulator with a flow check with a circulator without a flow check.

does the upstairs heat even if the downstairs isn't calling for heat?

Does the boiler make domestic hot water or just space heating?

Did it work before? If it did, make them fix it at their expense.

hot_rod

looks like it was a 3 zone system at some point? With zone valves.

Some lines in the slab have been capped

circulators on the return make it a little tougher to add checks

109A_5

" The thermostat upstairs will correctly track the current temp but will still circulate hot water consistently increasing the heat. "

This circulation, is the circulator for the upstairs running or does it correctly shut off when the thermostats call for heat ceases.

HVACNUT

Awesome. Someone ripped out the zone valves and piped in a flow control valve on a 45°. Thats terrific. The extrol location is great too. I can't tell if that 67 vent is attached to anything or just sitting on a fire stop stud.

Own or rent? Either way it needs serious attention. I wouldn’t touch it unless it was to replace everything.

mattmia2

is the knob on the flow check turned to the closed position? is there another one somewhere?

mattmia2

looks like there is a single flow check with both zones connected to it.

also is rocklath but just noting that from the size of the gypsum panels.

landryB

https://forum.heatinghelp.com/discussion/202516/boiler-thermostat-issue

https://forum.heatinghelp.com/discussion/comment/1870694#Comment_1870694

How can you tell it had zone valves previously and that the actuators are removed? Where would they be?

landryB

https://forum.heatinghelp.com/discussion/comment/1870743#Comment_1870743

I think this is flow check, correct? And it appears to be open.

There is not another one anywhere.

mattmia2

The flow check is not in the right place, that is your problem. There needs to be a separate one for each zone(and i think it might need to be installed vertically)

These are the valve bodies for zone valves that have had the actuators removed:

landryB

https://forum.heatinghelp.com/discussion/comment/1870700#Comment_1870700

Yes the upstairs will be heating when the downstairs is not. The set temp for downstairs is 65 and upstairs is 55.

boiler is only for space heating, we have a gas water heater.

Don’t know if it worked properly before, but it did work. The previous owners had no idea how it worked just that it did. They also had a tech come “service” it yearly. I also had this tech come out when we purchased it and he refused to do anything with it because of lack of knowledge. He said his “service” was him turning it on and making sure heat came out. I contacted a different company who has someone who specializes in boilers. They sent a tech with 20+ years of boiler experience who recommended the changes.

HVACNUT

https://forum.heatinghelp.com/discussion/comment/1871162#Comment_1871162

Three zone valves without actuators.