Baseboards hot in summer on oil fired boiler


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Old 04-11-17, 08:41 AM
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Baseboards hot in summer on oil fired boiler

I am a new homeowner with no experience with this type of system so forgive me if I use improper terms. I've read my systems owner manual and have had no luck.

My 2 floor home is heated with a heat pump that can heat the house through forced air, or baseboards with independent thermostats for each floor. For various reasons, we primarily keep the heat pump off and use the baseboards.

For some reason, the ground level floor baseboards have been remaining hot intermittently this spring despite the thermostat being all the way down, and it being hot in the house. The thermostats are the older round rotating honeywell style. These seemed to function properly in the winter. Below is a picture of my system.

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If I'm not mistaken the pipe on the front right is the primary discharge. It then splits off into two other pipes that seem to supply the two different floors. As pictured below.

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The pipe on the left remains quite hot all the way through that I can trace it with my hand. The pipe on the right is hot in the area pictured, but further down the line becomes cool to the touch. This leads me to believe These are my two zones.

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I believed these lines to be the return lines because while they are warm, none are as hot as the other lines mentioned. However those appear to have pumps, which I wouldnt understand being on that side of the system. Maybe I'm misidentifying the items.

For now I have turned the pictured electric switch off which I believe killed the pilot, and I have turned the oil supply line off at the tank to stop the problem, however I would like to know how to fix this, as I've read keeping the system off can be bad for it. I would also like to just plain have things functioning.

Sorry for the long post, but I hoped to be as thorough as possible, any help is appreciated! My knowledge is extremely limited and I hope to change that!
 
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Old 04-11-17, 08:54 AM
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Welcome to the forums.

Just turning the power off is fine. There is no pilot with an oil burner. It's not necessary to turn the oil off unless it's being serviced or there is a leak.

In your second picture those two green items are flo-check valves. They keep the hot water from circulating when the pumps aren't running. If these weren't there or weren't functioning... thermosiphoning would occur which is the circulation of water by hot water rising and cold water falling in the pipes.

In the bottom picture, in the lower left corner, are two circulator pumps. It's possible that one of them is running when it shouldn't be.
 
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Old 04-11-17, 09:15 AM
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Thanks for the fast reply!

I shut off the power switch which looks like it supplies the pilot, but I'm not sure if it supplies the pumps as well, though it looks like it may. I've read there could be issues keeping the system off over the summer with humidity inside the system or other problems? You don't believe this to be the case?

I suspected they may be flo-check valves based on my reading. Is there a way to test these myself? They seem to have some type of nut on top of them, but I'm not entirely sure that's the deal.

Is there a way to tell if these pumps are running? I've never dealt with pumps this small. I've not heard sound coming from them or felt vibrations. Is there a way to trouble shoot these?

It seems odd to me that the pumps would be on the return end, which then pumps the water into the same return line. If that were the case, why would hot water only come out one side of the system? Is there something I'm not understanding?
 
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Old 04-11-17, 04:09 PM
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FF,
Let's start at the beginning.

Oil burners have no standing pilot like some gas boilers do so you can turn your oil and power back on and don't worry about anything.

Next, the 2 green valves are indeed Flocheck Valves and there purpose is to prevent hot water from circulating through your system when your t-stat is no calling for heat in that particular zone. You should have 1 for every zone you have.

Because it is 1 per zone it is possible for 1 to work and 1 not to work which seems to be your problem.

You found the knobs on the top of each FC. They are there in case the FC gets stuck closed and doesn't let the water circulate when called for. The way they operate is when the stat calls for heat the pump will start which forces open the FC and allows water to flow through the zone.

The knob on the top should be turned all the way in for proper operation. By loosening the nut and unwinding the know it manually lifts the flapper in the FC and allows water to flow without the pump being on. Make sure nobody has opened your FC manually and it is turned on the way down.

The pumps on the return lines are no big deal and before this sudden craze the pumps have been on return lines for 50 years and worked fine on residential systems. They pull water from the return side through the boiler and out to the supply.

It looks as though you have a tankless coil to get your hot water. That is why you have FC's. Without them when your boiler came on to maintain temp for your coil it would circulate through the zone by conduction, the hot water rising and cooler water falling.

With the boiler hot if you follow the pipes they should be hot up to the FC and then cool off if the FC's are working. If the pipe continues to stay hot after the FC and into the baseboard you have a problem with the FC unless your pump is running.

If your pump is running the water would be hot all the way through the zone and back to the pump. If it's the FC follow the pipe to see how far it stays hoy before it cools down somewhere in the baseboard. Then you will know it's the FC.

You can check the pump by turning on the power and leaving the stat off. Take a screwdriver and put the metal end on the pump motor and the other end to your ear and see if you can hear the pump run. If you hear nothing have someone turn up the stat while you still have the screwdriver on the pump and you will see the difference.
 
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Old 04-12-17, 05:41 AM
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Spott, thank you so much for the detailed response.

I have followed the discharge line as far as I can and on what I can infer is the problem zone it stays hot the entire time up to the floors.

The return lines feel warm, one warmer than the other, but not nearly as hot as the discharge.

I will assess the pumps today, thanks for the tip. Still can't quite wrap my brain around how there are two pumps that run water from the return side into the same line, but that somehow effects the water being discharged out two different lines.
 
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Old 04-12-17, 06:38 AM
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Flo-Chek Valves ARE NOT "pumps"; they're installed just to inhibit natural convection within the pipes, or what PJMax referred to as "thermosiphoning".

If you have anything suspended in your heating fluid besides water, it may interfere with the movement of thin metal flapper inside the Flo-Chek that is used to discourage the flow of hot water up to the living quarters. I'll look for a cross-section of the Flo-Chek internals to better explain how it functions.

I've written about problems with my own Flo-Chek (especially during the Summer), and so far have been pleased with the improvement I experienced using a few gentle wacks with a rubber mallet !

PS: Here's a link to an explanation of how these convection inhibiting valves are supposed to work:

Surely, someone here has actually seen a Taco flowcheck operate?
 

Last edited by Vermont; 04-12-17 at 07:26 AM. Reason: Added PostScript
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Old 04-12-17, 10:59 AM
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Vermont,

Thank you for the response, I was able to find a diagram of the flo-check valve previously and believe I have a good understanding of them. I was referring to what appear to be, and have been identified by others, as pumps on the return side.

After attempting to manipulate the valve nuts, if there is no success I may try to give it a few whacks!
 
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Old 04-12-17, 05:10 PM
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FF,
Still can't quite wrap my brain around how there are two pumps that run water from the return side into the same line, but that somehow effects the water being discharged out two different lines.
I’m not one of the experts here, but I think one way to look at it is that when the pump starts to run it is kind of like sucking the water in and pushing it out of the pump. That makes it easier to push water towards the pump vs. when the pump is not running.

So when water comes out of the supply it will follow the path of least resistance, that is, it will flow towards the pump which is running.

I think it was mentioned before but I still think you have to eliminate the thermostat. It seems to me if the thermostat is bad it could be calling for heat even if you have it turned all the way down - hence the pump would run.

Maybe the other guys see it different.
 
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Old 04-12-17, 05:38 PM
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We have mentioned checking the pumps to the OP. He has acknowledged that.
 
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Old 04-13-17, 04:20 PM
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I mean directly eliminate the thermostat right up front. T’stat shorts, out of level (mercury stats), etc can produce a call for heat. Remember these are old thermostats. If it were me I think I would just swap the two thermostats and see if the problem moved to the other zone.

It’s easy to do, would allow you to check for wiring shorts while you are at it, and you don’t have the more difficult task (at this point) of trying to figure out if the pump is running by listening etc.
 
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Old 04-14-17, 09:37 AM
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Z,
He doesn't seem like he's to comfortable touching to much at this point because it is unfamiliar territory to him right now which is why I made the suggestions I did.

That being said when he followed the pipes to check for temp. he said it was hot on the supply and cooler on the return side which told me that the pump was not on since it would have been hot completely through the zone had the pump been running.

This in my opinion would eliminate the stat being the problem and most likely being the FC.

I agree with your suggestion as the easiest way to check the stat if he had a little more knowledge of the system but from what he wrote he had zero at this time so even trying to describe how to remove the stat for testing seemed a little too much at this point but it still may come to that.

Maybe a less complicated way to start would be to just remove a wire from TT on the aquastat which would give him the same result.
 
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Old 04-14-17, 12:48 PM
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Good points!!!......................................
 
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Old 04-14-17, 03:03 PM
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If indeed it is the flow/check, I have had trouble once or twice, and my remedy was to run the adjustment thumbscrew up and down, [after you loosen the lock nut. and return the screw to it's original position. That worked for me. I also use antifreeze in the system, and they might be part of the problem.
Sid
 
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Old 12-13-17, 10:24 AM
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Life got in the way of this repair, but now I am finally ready to address it properly!

Regarding the thermostat. I have not taken them off and switched them as at this point I don't have any knowledge of that but can learn if I need to. HOWEVER, they appear to be functioning properly as when they are turned up to a range where they should be calling for heat, I can hear the switch come on in the basement. With this audible indicator of the thermostat calling for heat, and my not hearing it when it shouldn't be calling for hear, leads me to believe they are functioning properly.

If indeed it is the flow/check, I have had trouble once or twice, and my remedy was to run the adjustment thumbscrew up and down, [after you loosen the lock nut. and return the screw to it's original position. That worked for me. I also use antifreeze in the system, and they might be part of the problem.
Sid
Sidney, I loosened and tightened the nut back to it's original position. Initially I thought this helped as the line did not immediately heat up after I turned the system back on. However, once I used to system for heat, I could no longer get the line to cool down by turning the thermostat off. Maybe I didn't give it enough time to heat up for the test? But this does not appear to be a solution to the problem. What does the antifreeze do?


I have spoken to a few friends who are DIY savy and they have all said that replacing the check valve is not something I can properly do myself if it is indeed bad (which at this point is what it seems). Does anyone know what I should expect to pay for this repair? The plumbers I have called have all refused to even give a ballpark price range over the phone and each want $100+ to come give an estimate. The one company that did give a range stated $800-1600! That seemed very extreme to me. Does anyone have any guidance?
 
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Old 12-13-17, 03:03 PM
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FF,
You have 2 flochecks (green valves). One for each zone and there job is to stop the hot water from getting into your baseboards unnecessarily when you only want domestic hot water.

If you're getting unwanted heat then one or both flockecks are bad. It's not likely both are bad so you should first find out which one is bad.

What I would do is shut down both stats completely and shut down the boiler and let cool.

When both supply lines are completely cool start the boiler just for domestic water and then run your tub for the hot water. While running the water go down cellar and feel your supply lines. They should both be hot up to the flocheck and NOT beyond them.

On a call for heat the stat will call and the pump will come which opens the flocheck to the zone that's calling for heat.

At no time should the supply pipe be hot beyond that FC unless the stat is calling for heat.

With the boiler running just for hot water and you feeling the supply line flochecks and beyond for unwanted heat will identify your problem area.

It sounds like a flocheck but verification is always good and to know which one.

The other way to identify it is to know which flocheck goes to the zone with unwanted heat.

Something to consider is if you have a bad flocheck you will get heat in that zone not only when calling for hot water but even if the other zone calls because there is nothing to stop the water flow when either pump comes on so that zone will be constantly heated.

So lets start by identifying the problem.

Depending on your skill level it doesn't look too bad to change it if need be.

Can explain later if interested. You must be able to solder pipe. The rest is just isolating and draining that zone, removing the FC, refilling, bleeding and putting back on line.

Hope this helps a little.
 
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Old 12-13-17, 04:49 PM
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Something to consider is if you have a bad flocheck you will get heat in that zone not only when calling for hot water but even if the other zone calls because there is nothing to stop the water flow when either pump comes on so that zone will be constantly heated.

So lets start by identifying the problem.

Depending on your skill level it doesn't look too bad to change it if need be.

Can explain later if interested. You must be able to solder pipe. The rest is just isolating and draining that zone, removing the FC, refilling, bleeding and putting back on line.

Hope this helps a little.
Spott,

I have taken some of the steps you mentioned to isolate the problem previously. I have not taken the steps regarding seeing if the baseboards in the affected zone get hot when the system calls for domestic hot water. However, the baseboards in the affected zone do get hot even when the other zone is the only one with an activated thermostat. Additionally, once the affected zone gets hot by having the heat called for appropriately, it will never cool down, and the baseboards remain warm as well as the corresponding piping for that zone past the check valve. Would these not be comparable tests? Or is there another part of the system that could be at fault that the domestic hot water test could expose?

I am a novice when it comes to these systems, however I am somewhat mechanically inclined and I take the time to learn to fix things.

My understanding is that in order to change the valve, the following needs to be done.

1. Drain the system entirely of water.
2. Cut the pipe downstream of the check valve
3. Replace the valve
4. weld a new piece of threaded pipe to the downstream end and connect to valve
5. Refill the system with water while also bleeding air from the system

Also, I don't know if it complicates things that I also have an electric hot water heater. It was explained to me that it serves as a backup. I haven't fully investigated it yet, but I would imagine there is a shutoff somewhere in the system between the boiler/radiator system and the domestic water system so I don't have to drain it all.
 
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Old 12-13-17, 07:22 PM
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The zone that constantly gets hot is the because of the bad flocheck. As I mentioned no matter what calls that zone will heat because with the defective FC there is nothing to stop the water flow to the units.

As long as it's only 1zone and you are comfortable the other one is operating normal you're fine. Nothing else would cause the problem you are having.

Now to change it if you can solder copper pipe.
1) Shut down down boiler and shut off feed valve so no water feeds in.

2) Isolate the good zone by shutting off the ball valve on the return line. The good flocheck will stop any water from the supply side into the boiler so that zone will stay filled and possibly no bleeding after
.
3) I would find a good spot where you can work and cut the copper tubing somewhere after the FC. The copper is screwed into the FC with an adaptor.

4) Remove the copper adaptor from FC.

5) Unwind FC from supply line.

6) Install new one paying attention to the direction of the valve. There is an arrow. They only work in one direction.

7) Screw copper adaptor back in to FC. using pipe dope or tape on all threaded connections

8) Connect copper back together using a coupling or copper union if you prefer.

9) Fill system and bleed zone.

10) Open all valves, turn on boiler and test.

That is the gist of it. If you're are more comfortable with another method of piping that's fine as long as it ends up basically the same way it is now. I can't tell how much room you have to work.

If you are mechanically inclined this is well within your wheelhouse.

Hope this helps a little.
 
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Old 12-17-17, 09:17 AM
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spott –

Additionally, once the affected zone gets hot by having the heat called for appropriately, it will never cool down, and the baseboards remain warm as well as the corresponding piping for that zone past the check valve.
................................
What can explain that (my italics)?

Shouldn’t there be relays somewhere which connect the pumps pictured to the thermostats? Looks like the thermostats turn the pumps ON/OFF independent of what the boiler is doing - but maybe I misunderstand the setup.

If that’s the case I wonder if there could be something flaky going on in the relay unit, and maybe as one last ditch attempt to eliminate the t-stat, the appropriate t-stat wire in the relay unit (if a relay unit exists that is, lol) could be disconnected for a period of time to see what happens – and then maybe later one wire to the pump could be disconnected from the unit.

But of course if no such unit exists that would be a tough job LOL!
 
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Old 12-17-17, 10:15 AM
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Z,
There are 2 stats and they do control the pumps individually but that is why you need Flochecks when using pumps.

Without the flochecks once a pump comes on it would circulate water to the whole system because there is nothing to stop the flow of water and so it just keeps circulating everywhere.

With flochecks installed there is no gravity flow and it takes the power of the pump, for lack of a better word, to open the FC and allow the water to only circulate in that one zone. That is why when zoning with pumps you need FC's and when zoning with ZV's you don't because ZV's are positive shutoffs and only open on a call for heat so if there is no call for heat they stay closed just like a ball valve and nothing can get by.

With a defective FC, that will not close it's like having nothing in the line at all so that zone becomes part of anything that calls, weather it is a call for hot water and the heated water circulates by gravity or if it is another zone. The water will always travel to that zone also.

A silver lining to this type of setup is if one of the pumps went down to a zone, creating a no heat situation, you could open up a FC manually and the one pump to the working zone would supply heat to both zones until the pump could be repaired avoiding an emergency call at night.

Hope this sheds a little light on this. Sometimes it's hard to explain in a post.
 
 

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