HELP! Baseboard Heat Problem

[Wise Guy]

I need help resolving an issue with baseboard heat. I am not an expert in baseboard heat, so my terms may be inappropriate or wrong. I'll try to be as accurate as possible.

The problem is quite simple. I am not getting heat where I am supposed to have heat. I have a two story farm house that has a single continuous line of baseboard heat. In other words, there is only one zone for the whole house, not two or more zones. Of course, the fins on the pipe don't extend throughout the entire house, but instead are in short sections in each room, but I need to be clear, there is a single continuous line of water that extends throughout the house. Here's the problem. When the boiler kicks on, I get hot water to every section on the first floor except for two, the kitchen and the living room. On the second floor, I get hot water to every section except for one bedroom. I have gone throughout the house to open the manual bleeder valves. At first I got a lot of air, but now all I get is water. I can't figure out why I am getting water from the bleeder valve, but when the heat comes on I don't get hot water. Again, when I open the bleeder valve in each room, I get only water, but for some reason I am not getting hot water to these three sections. Any suggestions? Thanks in advance for your help.

 

[maple1]

Are the sections without heat on the end of the run?

If not, that's really wierd. I can't see how that is physically possible if it truly is all one zone. Running hot water can't skip over one area of piping to the next.

 

[Wise Guy]

Maple1, thanks for your response. I think these sections are not at the end of the run. I'll try to describe the system as best I can without being too wordy.

In the basement, there is a single main artery. That pipe is about 1.5 in diameter. From that artery, there are several single loops going out to each room with a return to the main artery. Three of those loops don't get hot water when the boiler kicks on, but each of these loops is filled with water. Also, each of these loops has been emptied. I know that because I drained the entire system yesterday to fix a broken pipe. After repairing the pipe, I filled the system again before turning on the boiler. Of course, I got air from the bleeder points at first, but after a while water came through. When each bleeder valve seemed to give me only water, and I was quite certain the system was filled with water, I then turned the boiler on. This morning at 530 I awoke to loud sounds of water running through the pipes, suggesting that I still had air somewhere in the line. I opened each bleeder valve, and sure enough, I got air out of just about every bleeder valve. In time however, only water came out. However, I still don't have heat to three loops, the one for the kitchen, one for the living room (although I have two loops that heat the living room) and one loop that feeds the upstairs bedroom. The living room loop might actually be at the end of the main artery, but I am not positive about this as I did not install the system. Any further suggestions? Thanks

 

[Fred61]

I say it's air. Have you ever pumped liquid through a transparent tube and noticed a large and long air bubble taking up 90% of the diameter and still allowing a small stream of liquid to pass. That's what I think is going on here. That air bubble needs to be pushed out with a blast of higher pressure, higher flow liquid.

 

[Wise Guy]

Fred61, I agree. I think it's an air bubble too, but how would I get a blast of high pressure to the effected areas? I could simply open the bleeder valve in these effected loops, but the bleeder valves on these loops are awkwardly placed. The outlets are all facing either toward the wall, meaning you can't catch the water, or the outlet is facing the fins, meaning you can't catch the water. For what this is worth, I am not entirely sure that hot water has ever been through these loops. All I know is that water is there now, but no hot water runs through them. Any further suggestions? Thanks again.

 

[Bob Rohr]

Maple1, thanks for your response. I think these sections are not at the end of the run. I'll try to describe the system as best I can without being too wordy.

In the basement, there is a single main artery. That pipe is about 1.5 in diameter. From that artery, there are several single loops going out to each room with a return to the main artery. Three of those loops don't get hot water when the boiler kicks on, but each of these loops is filled with water. Also, each of these loops has been emptied. I know that because I drained the entire system yesterday to fix a broken pipe. After repairing the pipe, I filled the system again before turning on the boiler. Of course, I got air from the bleeder points at first, but after a while water came through. When each bleeder valve seemed to give me only water, and I was quite certain the system was filled with water, I then turned the boiler on. This morning at 530 I awoke to loud sounds of water running through the pipes, suggesting that I still had air somewhere in the line. I opened each bleeder valve, and sure enough, I got air out of just about every bleeder valve. In time however, only water came out. However, I still don't have heat to three loops, the one for the kitchen, one for the living room (although I have two loops that heat the living room) and one loop that feeds the upstairs bedroom. The living room loop might actually be at the end of the main artery, but I am not positive about this as I did not install the system. Any further suggestions? Thanks

What is the fill pressure on the boiler, needs to be at least 12 psi to lift the water to the upper level and have at least 5 psi at the high point. Does it have a working pressure gauge at the boiler? Sometimes bumping up the fill pressure to 20- 25 psi will squeeze those air bubbles and help push them along. Lower the pressure to 12 psi once you clear the air.

If you have a pump with multiple speeds, put it on high to try and move more fluid.

You need at least 2 feet per second velocity in a pipe to allow air to be pushed along with the fluid. In a 1.5 inch pipe you need to move at least 11 gpm to obtain 2 fps. Large diameter lines, especially vertical sections are tough to purge unless you have plenty of flow.

If the system has a fill valve it may have a fast fill lever, or a bypass around the reducing fill valve to allow more fill pressure and flow.

If you can isolate sections with valves it is easier to purge small sections one at a time.

 

[Wise Guy]

Thanks Bob. Yes, the pressure gauge is working and it reads 12psi. I don't know what it would mean to have 5 psi at the high point. I will bump up the psi to if that helps. I guess this begs a question. Given that the system has a main loop with several smaller loops attached, it might be that the system needs a higher psi setting. I'll have to give it a try and see. I will have to check to see if the pump has multiple speeds.

 

[Wise Guy]

Bob, I see that the pump is a Beckett. On the side of it, there seems to be a dial with a range from 2-10. The current reading seems to be set at 7. Is this dial to control water flow? Is this how I would increase the water pressure in the pipes? Thanks

 

[JP11]

Do you have any shutoffs at the manifold so that you can isolate each 'loop'

you could close the ones that are working off, and let ALL the flow blast the air out of the bound loops.

JP

 

[Thom Griffin]

If your piping is one big loop with several "loops" coming off of it, the water is going to follow the path of least resistance. When I installed my loops, I used special tees made that encourage the water to take the turn into the loop. I should add that I have a "two pipe" system, designed by an old heating engineer. There's a supply line that starts large and telescopes down as the distance from the source goes along, and there's the return, which starts small at the first piece of baseboard, and increases in size as it gets back to the boiler. This encourages equal heating along the entire path. I'm no heating professional, but I do teach irrigation, and know that you can easily have pressure in those cooler loops, without having flow, unless you are in the process of bleeding them. Assuming you have two tees for each smaller loop coming off of, and going back into your main loop, one solution would be to eliminate the section of main loop in between the two tees. That way, the hot water would have no choice but to flow through all of your loops.

 

[Fred61]

Do you have any shutoffs at the manifold so that you can isolate each 'loop'

you could close the ones that are working off, and let ALL the flow blast the air out of the bound loops.

JP

Or at least one at a time. You don't have a boiler drain spigot on the return trunk anywhere? Normal installation would have a boiler drain on the return just before entering the boiler that you could affix a hose to.

 

[Wise Guy]

Do you have any shutoffs at the manifold so that you can isolate each 'loop'

I wish it had shutoffs. There are only two shutoffs and they are on the main artery. Also, there are no special "T" connections to encourage proper water flow. The loops are sort of designed to encourage water flow to each loop, but since every loop goes straight up from the main artery, I can see how the water would not go into a loop. Why the systems was designed as it is, is a bit of a conundrum to me. Thom's suggestion that I cut away the main artery for these loops might actually be the only real solution, well the only real solution short of ripping it all out and putting in a new system with sever zones. Thanks for the advice.

 

[Wise Guy]

Having spent the past several hours draining water from each of the effected loops and seeing no air pockets, I am now fairly convinced that the problem is not an air bubble. When Thom suggested that I cut away the main artery to force water in through each loop, he made me look more closely at the configuration of the system. I noticed that the kitchen loop seems to have an inherent structural problem. The pipe leading out from the main artery and the return pipe seem to be about six inches apart. The loop is probably about 20-25 in total distance. I am wondering if the water simply bypasses the loop. The loop is filled with water, but the structure of the loop wont let the new hot water travel through. If this is the case, then cutting away the six inches of main artery will surely take care of the problem, at least the one for the kitchen. The exit and entrance pipes for the bedroom and living room loops are not connected to the main artery in the same way. I've bled these lines out too, but I still can't seem to get the hot water there. Cutting away the main artery in each these sections isn't such an easy fix either. The installers have returns in between the entrance and exit pipes on these loops. Any further thoughts? Thanks

 

[JP11]

A picture would help.

Water takes the path of least resistance. If you're saying there's a "shortcut" there. MAY be where your heat is going. Can you feel each 'loop' and see if some are warmer than others?

 

[maple1]

Why the systems was designed as it is, is a bit of a conundrum to me.

That sounds like a severe understatement with what you've described.

What would make the water enter the loops at all? Sounds like you've got closely spaced T's to feed the loops - but there are no pumps on the loops? Did they rely soley on convection flow to get water into the loops? Might be time for some pictures.

 

[Thom Griffin]

Some pictures would definitely help. I did the install on my system in '92, and as I explained before, there's some sort of special tee that I used that has a bit of a baffle in it to encourage flow into the loop going to either a radiator or a section of baseboard. It only forces some flow into it, not all of it. I don't recall seeing these tees at the big box stores. I always use a real plumbing supply house (usually cheaper too). Upstairs definitely won't see any flow unless you either pump it up there or force it by eliminating the sections in between the tees. The water will require higher pressure to go upstairs, so it will choose to simply stay in the main loop. It takes .43 psi more pressure to go up each foot of elevation rise.

 

[Fred61]

I purchased a 3/4 inch one at Home Depot.

 

[Bob Rohr]

Having spent the past several hours draining water from each of the effected loops and seeing no air pockets, I am now fairly convinced that the problem is not an air bubble. When Thom suggested that I cut away the main artery to force water in through each loop, he made me look more closely at the configuration of the system. I noticed that the kitchen loop seems to have an inherent structural problem. The pipe leading out from the main artery and the return pipe seem to be about six inches apart. The loop is probably about 20-25 in total distance. I am wondering if the water simply bypasses the loop. The loop is filled with water, but the structure of the loop wont let the new hot water travel through. If this is the case, then cutting away the six inches of main artery will surely take care of the problem, at least the one for the kitchen. The exit and entrance pipes for the bedroom and living room loops are not connected to the main artery in the same way. I've bled these lines out too, but I still can't seem to get the hot water there. Cutting away the main artery in each these sections isn't such an easy fix either. The installers have returns in between the entrance and exit pipes on these loops. Any further thoughts? Thanks

When was the system installed? Sounds like you could have a divertor tee, or monoflow system. Special restrictor tees are used to divert flow to each heat emitter. These can be a real bear to purge. Going to each vent multiple times may help if you have some emitters working. If it is a complicated piping you may need a high volume purge pump.

look for tees with special labels on them.

pictures would help.

 

[maple1]

If this problem arose after you drained the system I don't see how it can be anything but air. I have those little bleeders on my system & refuse to use them - the installers had problems getting them to stop leaking when my system was new & being brought online 18 years ago. So I'm not touching them. I do have a boiler drain on each zone though, and lots of ball valves. Must be air bubbles in low spots somewhere.

 

[Thom Griffin]

I purchased a 3/4 inch one at Home Depot.

Hello again Fred. I haven't needed one since '92; I just know that they didn't carry them at that time (in West Springfield). My Home Depot in Greenfield (likely yours too) carries an odd mix of stuff. If you go there, I'm sure you've noticed.

 

[Fred61]

Hello again Fred. I haven't needed one since '92; I just know that they didn't carry them at that time (in West Springfield). My Home Depot in Greenfield (likely yours too) carries an odd mix of stuff. If you go there, I'm sure you've noticed.

Actually I've purchased two in my lifetime. he first one from FW Webb and the second one from HD in Claremont NH which is about half the size of HD in West Springfield.

 

[Wise Guy]

Thanks for your helpful responses. The demands of life forced me to go silent for a time, so please accept my apologies for the delayed response. Maple1, your questions are precisely the ones I have. The plumbing system in the house is baffling to me. Other systems, especially the electrical system, also puzzle me, but that issue is for another day.

Here are three pictures to help explain the issue. In the first image, the one on the far left, you'll see the main artery and the exit and return feed to the kitchen. The distance between those two points is 10 inches. The pipe diameter for the kitchen loop is 3/4. The water flow in the main artery is from right to left. However, take a close look at the arrow on the first T. It points in the opposite direct. Isn't this a problem? Would the problem of no heat to the kitchen get solved if I simply changed the direction of the arrow? In other words, installed that T correctly? Or should I consider cutting the main artery too? In this first image, you can see a third T to the far left, and that brings me to the second image. In the second,middle image, you see another loop. This loop goes to the second floor. The distance between the two Ts is 12 inches. the pipe diameter for this loop is 1/2. It is interesting to me that this loop gets hot water. The water flow in this second image is from left to right. (you can see the return T from the kitchen loop on the far left of this image.) The arrow on the T in this picture points in the same direction as the water flow. The third image to the far right shows where I simply cut the lines of the loop. This loop went to the laundry room. After the pipes froze three times in a matter of a month, I simply cut the lines. Haven't had to fix that pipe for years. The water flow in the third image is from right to left. The pipe used to feed this loop also is 1/2. You can plainly see from these pictures that there are no pumps that feed the loops off the main artery; no ball valves either, just simple convection flow. There are other places on the main artery where the arrow on the T points in the opposite direction of the water flow. So, if the T is installed wrongly here in the first image, then I'll have to fix that and in the other places too. Thanks in advance for your help.

I have another related question. Would you advise using glycol in this summer/winter hook up to avoid future freezing problems even after I get the water flow problems corrected? I use a Hearthstone Manchester wood stove to do the primary job of heating my house. The boiler is really the secondary source of heat for me. Again, thanks for your help.

 

[Wise Guy]

Bob, thanks for the images. the image that shows the main artery and several loops, is basically the same set up I have here, with one important difference. Within certain loops, there are other loops. Or one loop begins and ends outside the loop, if that helps. I am wondering if a loop within a loop is an inherent problem.

 

[maple1]

I have no experience with diverter Ts. But if your Ts have arrows on them, that would indicate to me they are not 'regular' Ts and given where they're used would suspect they must be diverter Ts. And if the arrows are pointing against the flows I would also suspect they are installed wrong and won't work. That's my simple 2+2 deduction.

On your glycol question - if I had a hydronic system in my house I would use it, and get either a wood or pellet bruner hooked to it. I would not glycol it but instead make sure a suitable back-up heat source was also attached to it - for example an electric boiler. You just can't beat hydronic heat for heating comfort, especially compared to a space heater like a wood stove.

But you will have to decide that one. If you are sticking with the stove, and have had past freezings, you may have no choice but to put some glycol in it, or just empty the whole thing & abandon it - which seems a bit of a shame to me.

 

[Clarkbug]

Wise Guy,

Those are indeed monoflow tees. The idea being that you have your main artery, and within these tees there is a small "scoop" that diverts some water from the main into the loop. You absolutely need to have the tees with the arrows pointing in the right directions, so that they align with the direction of flow in the main. I am not an expert on Monoflow, but you probably dont want to have a loop feeding off of a loop as you mentioned.

Also, if you use a wood stove as your primary heat, glycol is probably a good investment for you to avoid frozen pipes. The alternative would be to rig up some controls to run your pump without running your boiler to keep the water moving when the temps get below freezing.