The recent cold snap has reminded me that the new Boiler that was installed in 1999 does not heat my house adequately. At 5°F outside, it cannot maintain 65°F inside. The old Boiler did but I don’t know its size or model number. No changes were made to the baseboard fin/tube system. There were 2 zones originally. The old one also supplied DHW. The new one has a separate Phase III indirect hot water heating/holding tank and is heated using a third zone . In 2006, a room was added above the garage and a separate zone was added for BB heat. That makes 4 zones total. In addition, the first floor splits into 3 sections, so there are 3 return line upstream of a single zone valve. Each of these returns includes a FLAIR Super Purge and Balancing Valve (jpg attached or see http://www.flairproducts.net/producthistory.html#superpurge). The second floor splits into 2 sections and no longer has the Flair Valves.
I understand the basics of how the heating system but am not very knowledgable about the details and need your help. Here are the facts regarding my system along with some test results:
House is approx. 4000 sq-ft and 30 miles north of Philadelphia.
Boiler is a Peerless WBV-04 at 178,000/155,000 BTU/Hr, output/rated.
There is one Taco circulator for all 4 zones. I don’t see a model number on it but its powered by a GE 1/12 HP Motor. (I would thing this isn’t a good design as the flow rate will vary by up to a factor of 4 depending how many zones are calling for heat.
Aquastat (Honeywell Model #L7124) is set at 190°/160°/10° for high/low/diff.
Temperature gauge on boiler is 170° when it turns on and it shuts off at just below 190° but the temperature continues to climb to just about 190°F. I’ve read that the lower this temperature, the less heat is lost through the chimney. However, doesn’t a lower temperature of the circulating water reduce the heat output of the baseboards?
The following temperature reading were made with an IR “gun” type thermometer with unknown accuracy.
Discharge temp (with boiler at 190) is 170°F
Return temp (with boiler at 190) is 135°F
On that day, it stayed on for about 5 minutes and circulated for 8 minutes before the boiler turned on again.
Individual returns when main return was about 120°F:
3 (new room above garage): 85°F (probably not calling for heat)
4 DHW: 125°F
I think the FLAIR valves might be contributing to the problem, but the heat on the second floor is not adequate so that’s not the only thing that is wrong.
What suggestions do you have and/or what additional information do you need from me to evaluate this problem?
Also, in the summer, the boiler still cycles on and off 3 or 4 times a day, even when DHW isn’t being used. Is this just to maintain the boiler at 170°F or because the DHW tank temp has dropped to below its 120°F setting and is calling for heat?
Below is the text of FAXes I sent 14 years ago to the company who sold and installed the new bopiler. Much of this text is just a repeat of the above.
Since 2000, it hasn’t gotten as cold so it hasn’t been as much of an issue.
Jan 24, 2000
I am not happy with the new Boiler I purchased from your company last October to replace my 25-year-old Boiler with a top of the line model. However, on 4 or 5 occasions this winter, the house has been colder than it should be. The 3 or 4 service visits all yielded the same results: The serviceman watches the Boiler turn on, the water temperature gauge increase to 205°F (I increased it 5° or 10° at a time from 180° as suggested by your company) and then shut off. Then they check with their hands to see that he radiators are warm. Then they say something like: “There’s nothing wrong with the Boiler. It’s just very cold and you can’t turn back the thermostat and have the house heat up.” I think something is still wrong. When it is cold, the Boiler can’t even hold the set temperature in the house.
I have two Honeywell Model CT3400 Thermostats. They allow for four temperature settings each on weekdays, Saturdays and Sundays. These thermostat record the heating rate and actually call for heat earlier than the set time so the temperature is reached by the set time. In order for these thermostats to work properly, I was instructed to install a relay at each zone valve being controlled. Since installing the new Boiler, I have had to increase the turn-back temperature from as low as 50°F with my old Boiler to 66°F now. Here is an example of how it used to work and how it works now:
When going away for winter weekend’s two years ago (1998), the thermostat was set at 50°F for Saturday and Sunday until 4:30 PM when it changed to 71°F. This 4:30 setting should bring the house to 71°F by 4:30PM. When returning home, the house was 71°F no matter how cold it was outside. This past weekend (in 2000), the turn-back setting was 66°F instead of 50°F. Again it was set to reach 71°F by 4:30 PM. When we arrived home at 7:30 PM the temperature was only 69°F inside with an outside temperature of about 25°F. I think the new Boiler should be able to heat the house to 71°F easily when the outside temperature is seasonable.
Last January (1999), your company replaced a leaky circulator. The new one was much smaller than the old one. The house didn’t heat well at all. I called another company and their service man found that the Boiler set temperature was lowered for the replacement but not returned to the proper limit. He reset it but it didn’t seem to work as well as the old one but I didn’t complain about it.
I remember having my heating system checked while I lived in Massachusetts. Their serviceman used some sort of thermometer to check the temperature of the radiators. Perhaps you need to do that as well to make sure the system is working as efficiently as it should. I expect another visit to make my new system work as well as the old one. I’m not sure exactly how you should check to find what is wrong but here are a few places to start:
The circulator is undersized
The circulator impeller is uncoupled from the motor and all we are getting is natural circulation.
The zone valves are not opening fully.
There is foreign material partially blocking the flow.
The Boiler temperature gauge is inaccurate.
The Thermostats don’t work right for this type of Boiler Control System.
Again, these are just my ideas. I think it is your company’s responsibility to get the new Boiler to work as effectively as the old one.
Jan 28, 200 Fax
Your service man, Rich, visited on Wednesday and installed a larger circulator. Using thermocouples he tested the outlet and return temperatures. There was a significant improvement and I thought the problem had been solved. It hasn’t. The first floor zone was set to be 65° overnight, to rise to 67° by 5:50 AM and 71° by 7:20 AM. At 6:30 it was 63° and by 7:00 AM, with the thermostat calling for heat, the temperature had actually dropped to 62°F. Now, at 10:00 AM it’s only up to 65°F.
Here is what I plan to do next:
Put new batteries in the Thermostats
Increase the Boiler water temperature (the silver wheel in the Honeywell controller indicated 195° but the temperature gauge read 205°F. Perhaps the gauge is not accurate. I have raised the temperature to 205° on the wheel, which give an indicated 215° on the temperature gauge.
Vacuum the radiators to improve air circulation.
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