No heat in the part of the house

Hello Everyone,
I originally thought I had an aquastat issue where I wouldn't get heat in half of the floor when zone valve is set to Auto mode. I do get heat when Zone valve is in Open mode.

Here is the scenario. I have three family house. Each floor has it's separate zone valve/Thermostats. 1st floor works fine, 2nd floor works fine except 1 room and 3rd floor only front of the floor works, rear bedrooms and bath have no heat.
I thought there was air in the system so purge the system for all three floors. I noticed on my 3rd floor rear baseboards getting warm and it would stay warm for sometime. Later it stops working. I change the Zone valve to Open for all three floors and i get heat everywhere. It gets so hot that I have to open the windows.
I am trying to find out is it my zone valve that has gone bad for 3rd floor or do I have air in the system that I need purge out for 3rd floor?

 

If you turn the 3rd floor zone valve to open and leave the other two in auto, do you get heat on the third floor?

If you turn the thermostats for 1st and 2nd floor way down so they are not calling for heat, and turn the 3rd floor thermostat up so it is calling for heat, does the circulator pump run?

What is the pressure reading on the boiler pressure gauge?

Do the convectors have bleed valves and is that how your purged the air? Did you get water out of all the convectors?

This information will help narrow down the problem.

 

Thank you Carbide Tipped for your response.
1)To answer all your questions. I left the 3rd floor zone valve in open and other in auto. I do get heat on 3rd floor but only in the half of the floor where it works. Rear has no heat.

2) didnt' perform this test

3) Pressure is less than 10 almost nothing. Water temp is also down to zero. Circulator pump isn't running. I have to manully push the water in to the system to increase the pressure.

4) I purge the air from the return pipes near the boiler. None of the baseboards have bleed valves.

I recorded some videos which will give you some idea of what I am talking about. I will add the youtube links in the new post.

 

here is the overview of my system on you tube. https://youtu.be/RGR5zqpMVr4 I have other sets of videos which you can see what I did to troubleshoot.
https://youtu.be/F01PkxbBQzI https://youtu.be/f_3Be09Bg8c https://youtu.be/P5J0CwcNCrU https://youtu.be/b7CxEjPP6ck Last but not least, I try purging air out for the return pipe for rear part of third floor. Still no dice.

 

Before going any further please read:

CounterPoint How Hydronic System Components Really Work B&G[pdf]

 

Seems like I have fix the issue. I purge the air just from rear part of the third floor. I purged for a longer period then usual and it seems to have fix my heat issue. All zone valves working fine in auto mode.

 

I am back again with the same issue. I have no heat on my 3rd floor rear part of the floor. Last time I thought there was air in the system so I purge the air from the return of that section of the floor. Now I have no heat on half of my 3rd floor. I do occasionally hear the very light knocking noise in the baseboard when the heat is on but it doesn't get warm or hot. What could be the problem here? Can anyone recommend a repair person who knows the hydronic system? I am from Jersey City, NJ.

 

You've got a pressure problem which is why the air keeps getting trapped upstairs.
You need more then 10 psi cold for a 3 family home, bump it up to at least 15-18 psi cold.
You might have a faulty auto fill valve, or it just might need to be adjusted.
Verify that the boiler's pressure gauge is correct, see the sticky on top of this forum for the how to.

 

Thank you Tomf63. I will try to increase the pressure and see if I get any heat. Let's say If I do get heat after increasing the pressure. What could be the problem since it was working for few days. Couldn't be i have a issue where the pressure is loosing somewhere?

 

If you are losing pressure then you obviously have a leak somewhere.

Look on the boiler nameplate and it should state the Maximum Allowable Working Pressure or MAWP. This will be a number between 30 and 60 psi, most likely 30 but could be higher. Tell us this number.

Your aquastat may well be defective. What is the highest temperature reading that you have observed? What was the pressure at that temperature?

 

Highest temp on the gauge I have see is around 140 degrees. Right now it's at 140 pressure is below 10. Motor is running and burners are going on and off to maintain that temperature.

On the name plate it says:
Minimum safety relief valve capacity 96 lb/hr
ACME MAX WORKING PRESSURE WATER 30 PSI STEAM 15 psi.
I am setting the pressure to around 25. Let's see if it stays and give me heat at my cold areas.

 

What type of "heat emitters" do you have? Finned baseboard convectors are rated with 170 degree water and at 140 degrees they don't work very well.

Required pressure can be calculated by measuring the vertical distance from the base of the boiler to the highest point of the highest heat emitter in feet. Multiply that by 0.44 and then add 4 to the result. Example: 26 feet vertical height time 0.44 equals 11.44 and then add 4 to come to a MINIMUM pressure at the boiler of 15.44 psi. Round up to 16 psi as the minimum cold pressure. Pressure at rated temperature will be higher, how much higher dependent upon the amount of water in the system and the size of the expansion tank. Maximum pressure for your system is 27 psi which is 10% less than the MAWP or safety valve setting. That means the operating pressure range is from 16 to 27 psi. Your numbers will be different based upon the vertical distance previously described.

I would have to look back on the videos to see if I can determine the means/method of changing the temperature setting on your particular aquastat but it should be fairly obvious when you look. There may be more than one dial to set and you want the cut-out to be at 180 degrees with the differential about 10-20 degrees lower. Posting some still pictures of the aquastat may help.

 

I have baseboards thorough out all three floors. It's 11:30 PM and went down to take some aqua stat pics which I will upload tomorrow morning. Pressure dropped down to between 10 and 15. Temp was still at 140.

 

1) Stop Purging:
Cold city water entering the system has 2% dissolved air in it, when the temperature of the water rises, that air comes out of solution. Every time you purge, you add more air (adding cold water = adding air.)

Service or replace the air vent on top of the boiler, where do you think all that damages to the hood is coming from?
If the vent is dirty it can spray a fine stream of water that is very hard to see.

2) Alow boiler to cool to 100F, add water to raise system pressure to 12-15 psi.
Close the isolation valve between the boiler and the pressure reducing valve.
Open air vent on boiler and run system.
Use the isolation valves on the return manifold to force flow to each leg of a zone.

 

Thank you Heatworm and Furd for the help.
I have been increasing the pressure which add more city water into the system. I did that again this morning since the pressure dropped. I'll stop doing that. I have a gate valve which I am not sure if it still works, after the manual feed and motor/boiler. Youcan see it in this video
https://www.youtube.com/watch?v=f_3B...ature=youtu.be
I am not sure how to service the air vent. I do keep the little knob piece little loose to allow air to escape. Not sure what else to do with it. What
Here are the pictures of the Aquastat.

 

Losing pressure that quickly you obviously have have a leak. Try screwing the "tire valve cap" on the air vent down tight to see if this is where you are losing.

Use a screwdriver to turn that screw in the aquastat that has the temperature ranges around it. It looks like it is set for 180 degrees but it is not abnormal for them to lose calibration. Turn it only to the next mark and then see how hot the water becomes. It is also possible for the thermometer itself to lose calibration and the same is true for the pressure gauge.

You may need to change the pressure/temperature gauge as well as the aquastat but first let us see if you can make it through the winter with what you have. This is not the time to be doing major work on the boiler or heating system.

 

I moved it to190 on the aquastat. Water temp increased to 160 degrees.

 

If you have one of those oven thermometers that has a remote probe (or are willing to buy one) you can use a hose clamp to fasten the probe securely to the boiler outlet piping and then wrap some fiberglass insulation around it to check on how inaccurate the boiler thermometer is.

For now I suggest that you move the aquastat setting one more mark higher and see where the temperature stabilizes. Also see if you get better heating throughout the house with the higher temperature. Watch it carefully, check several times a day as you do not want it to exceed 200 degrees under any circumstances. Watch the pressure also and you can also get another gauge and connect it to the boiler drain valve to check the accuracy of the boiler gauge.

 

Is this the gauge i need?
PEX - Radiant Heat - Radiant Heating - Plumbing Supplies - SupplyHouse.com

 

I think Furd was suggesting you use a gauge like this attached to boiler drain (and then open drain valve slightly) as a quick test of the accuracy of your built in gauge.

Amazon.com : Rain Bird P2A Pressure Gauge : Pressure Washer Gauges : Patio, Lawn & Garden

The range isn't ideal, but good enough for a quick check.

 

Thank you for the link. I placed the order. So after increasing aquastat to 200, tempratrue on the guage got up to 200 degrees. I did it yesterday morning and when i came back from work heat wasn't working. Motor was running and temperature was hight close to 200. None of the pipes were hot/warm. So switched back to my default setting and put the zone valves in open mode. I know you guys suggested not to add water into the system but I did it anyway to increase the pressure. I put it in Open mode to see if I get heat in the rear part of the 3rd floor. There was no heat. In the past it use to work in Open mode now it doesn't do that.

Is it poosile that there is a leak in the boiler itself? Or could it be this boiler fill valve. Mine looks something like this.

 

Most definitely! In fact, if there are no signs of leakage anywhere else then the boiler IS the likely spot for a leak. Unfortunately, a leaking boiler usually requires replacement, especially a cast iron boiler.

You aren't one of those people that turns off the main water valve whenever you leave the house are you? That's about the only way that you would have a backward flow through the pressure reducing fill valve.

What was the pressure when you found the temperature close to 200 with the pump running but no heat? At this point I don't think you have a problem with the zone valves so much as you have a problem keeping the pressure up ion the system. If your system is set up in any kind of "normal" manner the room thermostats will control their respective zone valves and the zone valves signal the aquastat to start the pump. If the boiler temperature is below the aquastat setting it will also cause the burner to fire. The one thing wrong from everything you have posted has been the pressure. You MUST have a minimum pressure as I previously described for the system to transport the hot water from the boiler to the heat emitters. Without that minimum pressure you are just spinning your wheels.

 

Pressure was around 10/15 PSI. Doesn't go high or low from that mark. I do not turn off the water when I leave my house. It's a three family home/3 floors. I rent out my 1st floor so there is no chance I would do that. If the boiler itself has a leak, how come I don't see any water on the floor?


What's a normal life of these boilers? This one probably came with the house built in late 60s / early 70s. I have been looking around for cost and boilers start around $1800 and goes up to $5000.

Should I start getting estimates and get it change this winter season or wait till summer?

 

That's not good enough. You need precise measurements. I suspect that the boiler-mounted gauge is reading incorrectly. You need a 0-30 psi gauge, a female garden hose thread adapter and other fittings to connect the gauge to the adapter. Then you can screw the gauge to the boiler drain or one of the zone purge valves to get a true reading of the pressure.

Did you measure and do the calculation I suggested to determine the minimum pressure needed?

Some people are scared to death their pipes will break when they leave the house and so they do turn off the water. I have to ask.

It may only leak when hot (expansion of a crack) and then evaporate as fast as it leaks. It is not uncommon for this to happen.

I don't know. Some residential boilers are still working just fine 60 or more years after they were installed. Others never made it to 20 years. Leaks and continually having to add water is very bad.

I think you should find the problem first. You MAY need a new boiler but it could be just a few adjustments and maybe a couple of parts will fix it up for the next several years. I almost never recommend replacing the boiler during the heating season for several reasons. You already know that the aquastat is out of calibration and possibly ready to fail completely. You know that the pressure gauge cannot be trusted. The thermometer is of dubious value as well. In addition you may have some thermostat and/or zone valve problems. You need to have a systematic plan of testing each and every part and then actually do the testing. This is not brain surgery or rocket science but it DOES require a logical approach. The test gauge for the pressure problem is the place to start.

 

Can you inspect the pressure relief valve discharge piping, the end and the floor below it.
We did not get a good view.

 

I haven't done the calculation. I don't have enough time to troubleshoot this issue. Should I just buy new zone valve for 3rd floor and a new aquastat to rule it out?

I am waiting for the new gauge to arrive. Once I do the pressure test at the drain valve we should know if the boiler itself has any issue???

@Heatworm I will post more pics later tonight.

 

YOU can do as you please, it is a free country, more or less. If you are happy spending money and changing parts in the hopes that you will stumble across something that fixes the condition then who am I to stand in your way?

I wouldn't do it that way but then I seem to have a different philosophy than you.

I wish you well.

 

I didn't mean to offend anyone. Just thought there would be easy fix by replacing parts. I know you are all trying to help here.

I ended up doing the calculations for the pressure. Like you said I estimated the distance to be about 55 feet to the Highest heat emitter. So the required pressure came out to 28.2 PSI??

I am adding pics of the Pressure relief valve and the circulator motor. I noticed that motor has some water leaking. Can the pressure be lost there? It's not leaking water but just noticing wetness in the area.

 

I'm not offended, I just don't understand the thought process, or more to the point, a lack of thought that causes a person to just start changing parts rather than think the problem through to a logical conclusion.

Yes, the wetness around the pump signifies a leak. It may be evaporating fast enough that it doesn't leave a puddle on the floor.

Are you sure about the 55 feet of height? Even if we drop the 4 psi "fudge factor" that leaves you with a 24 psi minimum pressure and that leaves you with almost no room for expansion. As I stated in an earlier post the absolute maximum you should run that boiler is 27 psi which is 10% below the safety valve setting. 50 feet would bring the minimum pressure down to 22 and with a 2 psi fudge factor raise it to 24, a much better number. Otherwise, that boiler should never have been installed in that house but one with a higher MAWP installed instead.

 

Correct... I have 3 floors with no basement. Heating system is located in the back of my garage. I counted the floor to ceiling height for 3 floor and the rear part of my third floor which is the last part of the house where the heat reaches. Let me know if I miss something.

 

Just to update on the current situation. Now the heating system goes cold down to 0 degree pressure below 10PSI. cirulator pump keeps running but no heat. I even put the three zone valve in open mode but still no heat. I had to wiggle the relay switch on the aquastat to kick off the burners. I finally got heat. Still no heat on rear of the 3rd floor.

 

Is your garage underneath the house? Generally I figure a distance of about ten feet from the finished floor to the next higher finished floor. I get this height from the standard eight feet from floor to ceiling and then adding the void space where the floor joists for the next higher floor are positioned. Even that should be only about another foot so in reality it is usually closer to nine feet from finished floor to finished floor.

If your garage is below your house you may have as much as 10 feet from the floor to the ceiling in the garage and then 9 feet more to the second floor and an additional 9 feet to the third floor. That would add up to 28 feet, or 30 feet from the floor of the garage to the floor on the third level if you use the 10 feet per floor figure. Add another 5 feet if you have cast iron radiators and you have 35 feet. 35 feet multiplied by 0.44 equals 15.4 plus 4 equals 19.4 psi or rounded up 20 psi minimum pressure. Of course if you have a 15 foot ceiling on the main floor and 12 foot ceiling on the second floor the numbers will be higher.

Even if you had four full floors the total height should be only about 45 feet which would correspond to a minimum pressure of 24 psi.

Now IF your garage is on the same level as the first floor of the house (if it is an attached garage it is probably 18 to 24 inches lower) AND you have those 16 foot ceilings on the first floor plus 12 foot ceilings on the second floor it would put the third floor a maximum of about 32 feet above the garage level. Add the 5 feet for the radiator and you still only get 37 feet total height.

Still think you have 55 feet?

 

Okay, you posted while I was playing with numbers.

You MUST keep that pressure up. That is an absolute. Until you can find and solve the problem of the falling pressure you will get nowhere. The aquastat, more likely as not has a problem and may need replacing but until you fix the pressure problem you just plain don't know. Same with the zone valves, you just can't know until you fix the pressure problem.

 

Are you suggesting i change both aquastat and 3rd floor zone valve?

My garage and 1st floor are same level. Garage is in the front and 1st floor apartment behind it.

I guess you may be right about 35ft. I was counting about 10 ft between each floor and add additional to rear of the 3rd floor which has the furthest heat emitters.

 

No, I am suggesting that you find the reason why you are losing pressure, most likely due to a water leak, and fix that problem. Until you fix the pressure loss problem you cannot be certain of ANYTHING else about the system. The zone valve MAY be defective but you cannot be sure of that UNTIL you fix the pressure problem. The aquastat MAY be defective but replacing it will not fix the pressure problem.

Horizontal distances are irrelevant, only vertical distances are important when calculating the minimum pressure needed.

 

I don't see how I would resolve the pressure issue. Only thing i can think of is the boiler itself. I'll wait till i get the pressure gauge.

 

Last Friday in post #22 I told you that is was a definite possibility the leak was in the boiler. This morning you posted a picture showing evidence of a leak at the circulator pump.

 

My heat issue has been resolved. Past weekend we went through a Polar Vortex where temperature dipped below Zero degree Fahrenheit. I had 3 water leaks in the system due to frozen pipes. I got those leaks fixed and changed the expansion tank for the heating system. We filled the system back up and bleed all the floors to makes sure no air is in the system. All my floors are getting heat.