New radiator installed. Oil furnace shuts off after 5 minutes.

FrozenNorth

Hi,

I just had a new hot water radiator installed. However, now the furnace won't stay on in the house for more than 5 minutes (the last time we used the heat was four months ago so I am not sure these things happened back to back.) After the furnace shuts off, the reset button won't work. I can shut the power off to the furnace and a few hours later get the furnace to come on again by flipping the power switch back on (the reset button doesn't work). At the time the furnace shuts off, the pipes coming out of the furnace are hot for about 4 feet (up until the first red "tap", then all the other pipes are cold). The furnace repair guy came and he says it is the fault of the radiator installer, that there is air in the system so the water won't circulate so it gets too hot and shuts down. We brought the radiator guy back and he re-bled every radiator with me beside him and there is no air in the radiators. So I called the furnace repair guy back and he said the furnace is fine, it comes on, he can feel the circulating pump vibrating, and it will work when I get the air out of the system and he wouldn't come back. The plumber guy says there is no air in the system.

Is it possible there is air in the system even after every radiator is bled a cup of water and no air comes out?

I googled my problem and read that if the furnace shuts off after 45 seconds it could be the flame rod detector or cad cell relay control (?) But mine stays on for 5 minutes so it seems like the flame is being detected.

Is there any other possibility that would explain why the radiator comes on, runs for five minutes and shuts off? We have 1/4 tank oil, the fuses and electric panel is fine, the tech said the furnace thermostat is fine (he was able to turn on the furnace with it) and I reset the thermostat upstairs and it will turn on the furnace.

Any advice would be really appreciated!

JUGHNE

Do any radiators in the house get hot at all?
What temp does the boiler get to before it shuts off?

If water is not moving thru the boiler it will shut down on high temp, and without water moving it will take a long time for the iron to cool down to reset the temp control inside the boiler.
Maybe a valve got closed that keeps the water from moving.

Pictures of the boiler piping & valves could help, back up for wide view.

Especially the "red tap" you mentioned.

STEVEusaPA

"...it comes on, he can feel the circulating pump vibrating..."
This doesn't mean the circulator is working. I can't believe a heating guy would come out twice, not confirm the circulator is working, and not purge the system of air.
It's possible replacing the radiator loosed up something that is now lodged in the impeller, so the circ isn't working...or the circ just isn't working.
The reason why your reset button wouldn't work is because your burner didn't shut off for flame failure, but because the high limit shut it down.
Good news, that's working.
Bad News:NEVER PUSH THE RESET BUTTON. IT WILL NOT FIX YOUR BURNER. In fact you can easily and quickly create a very bad, dangerous situation. If you're burner went off on reset it means something is wrong and the best thing you can do is leave it that way until a qualified tech (not your guy) can show up and watch what happens when it is reset.

Ironman

Is this a Monoflo system? If so, it can be extremely difficult to get the air out.

What your describing is a no flow condition which will cause the boiler to shut down on high limit. The likely causes are:
1. Air in the lines. This is the most likely since the problem started immediately after a rad was added.
2. Bad circulator.
3. A valve closed.

The "Reset" button has nothing to due with your issue. As Steve said, it trips when there's a flame failure. Please leave it alone.

Please post some pics of the boiler, its near piping and the main line where the radiator tees into it. Particularly, a close up of the tees to the radiator.

Paul48

Depending on the radiator and how they are plumbed, it can be impossible to purge the air from the system by bleeding each radiator. A qualified plumber/technician would know how to best purge the system. You have yet to deal with either.

HVACNUT

A lot of monoflo systems don't have purge stations. I have a feeling that's why the "furnace repair guy" didn't want to touch it.
The radiator installer might need a helper. Turn on the heat, boost pressure to 25 psi and start bleeding rads while maintaining 25 psi. When all is hot, drop the pressure back down to 12-15 psi.
In any event, it's up to him to make it right. Things were fine before he knocked on your door that day.

EBEBRATT-Ed

Amazing.
The plumber and the tech pointing fingers at each other.

The plumber is INCOMPETANT . he shut down a working system and can't get it working.

The technician is LAZY. He was called their to diagnose a problem. The problem may not be his to fix, but he should have found the problem. He got paid to go their

FrozenNorth

Thank you so much for your responses. I am attaching photos, one of the furnace from the front, one of the pipes behind with the red tap, and one of the floor connection between the water pipes and the radiator pipes.

When the furnace starts the pressure is at 15psi and the temperature on the furnace at 100degrees. When it shuts off the pressure is at 20psi and the temperature is at 130.The pipes are hot to the red tap, and all pipes are cool beyond that (the tap is open). No radiator in the house gets any heat. (I don't know how to crank up the pressure, but I assume the plumber should.)

I don't know if this is a monoflo furnace. The manual says that "air can be bled from oil lines from the bleed port on the oil pump". The manual also says that if ignition fails "Check for air in the oil pump suction line" (how?). Could replacing a radiator affect the oil pump suction line? Another question: could the radiator have been installed wrong, i.e. in a way that could cause this problem?

Thank you for taking the time to help! .

JUGHNE

By the "red tap" do you mean the red handle on the valve above the red pump on the pipe on the back of your boiler?

You say the red valve is open? That is counterclockwise turning if you are standing in front of it.
Try to close it and then open it again.

That type of valve can have a problem of coming apart on the inside and not opening as it should. The installer may have closed it and when it was opened again the internal parts could have come disconnected.

This problem has nothing to do with your oil burner, oil pump or air in the oil lines.........it is a water flow thru the boiler problem.
I would suggest that you never try to do anything with the oil burner that fires into the boiler....IF needed in the future to call some oil burner service company......not the 2 who can't figure out what is currently wrong.

The oil burner and boiler is doing what it is supposed to do when you ask it to run and the water does not flow thru the boiler to remove the heat. It gets up to a certain temperature and then shuts off. When it cools down it will heat up again.

Could you post pictures of your new radiator and one or two of the existing radiators?

Note: also picture of piping in the basement under a radiator.

Leon82

Are those braided hoses going into a radiator? I remember reading that they aren't an oxygen barrier

JUGHNE

As we await more pictures just a thought:
When you do call someone for service and repairs on your system, You should state that you have an "Oil fired boiler".....a completely different animal from a furnace.
We here understand what you have, but calling someone new on the phone and using the furnace term, they may send out the furnace team who may never get near boilers.
(they may have already been there)
Perhaps in your area boilers are referred to as "furnaces", but the term boiler should clarify your meaning anywhere.

STEVEusaPA

I can't believe a licensed plumber would hook up radiators like that, but I'm never surprised anymore. I also agree with @Leon82.
I would try to get a pro in there, someone who knows oil & hydronics (maybe you're oil supplier.
It's obviously lack of flow by one or more of the following:
-Bad circulator
-Bad control not sending power to the circulator
-Air in system
-Not enough water in the system.
-Possible sediment blocking circulator and/or stuck flow check

And back to my original statement of:
Verify the circulator is working, I would add:
1. Replace the braided lines, it's hack work and it will eventually fail. It looks like it's behind a wall with limited access so you probably won't know until you have a big mess.
2. Properly purge. I doubt it's monoflow.
3. It appears this radiation is below the boiler, I would add a low water cut-off to the system, or replace the aquastat with one capable of low water cut-off. I would seriously not let either of the 2 people in the house to do this as they appear to be stumped by what's going on.

Way back to your original post, is this a newly installed radiator where there never was one (added to the system), or just a (not-so) simple radiator replacement?

Ironman

It appears the new radiator is a panel rad that been connected to old piping, so there was probably some form of radiator there before.

@FrozenNorth
Can you post better pics of the piping around the boiler and also of where those two black pipes that are going to the rad are connected on the other end?

Also, make sure the red valve above the red pump is opened all the way.

To reiterate what's been said: this is a water side problem, not a burner problem. The air we are talking about is in the water lines, not the oil lines.

Grallert

Washing machine hoses??? Seems like a really bad idea.

FrozenNorth

Thank you all so much for your responses! I managed to get the senior plumber associated with the heating company to come out since I was getting nowhere with the tech and the original plumber.

After looking at things he concluded the circulating pump needed replacing, and suspected the pump is running but the impeller not turning. I asked him, based on comments here, if it could be the valve and (to his credit) he thought about it and checked it out. After doing that, he changed his mind and said it is likely the valve because it makes a clicking noise and moves even when it is screwed all the way in, so now he thinks that it may have come apart inside and may be stuck shut even when it looks open. He said it could still be the pump but he can't know for sure till he empties the system Friday.

Thank you all so much for those useful comments. They really helped me begin to grasp our heating system and also helped me get the plumber to look deeper.

I'm disappointed that those flexible pipes to the rad are a bad idea; although the access to the rad is tight, cutting away more of the floor and furnace room ceiling was an option (the plumber who installed it was accessing it from below, in the boiler room). In our area, pipes are required to be 100% copper but when he said he was going to do the flexible pipes because it was tight for welding, he seemed pretty casual and I didn't know there was any downside. The senior plumber who came thought the flexible pipes wouldn't be so bad since the radiator is really small (12 x 15 inches whereas the original one was 34 x 30). But he predicts it will warm up slow and not give off enough heat :-(. I'll know for sure in February. If those pipes do start to leak, I will notice, because they are right above the bench in the boiler room where we sit to take off our boots. (Small consolation.)

I'll let you know Friday what the issue was finally, assuming the problem is successfully fixed..

Ironman

The flex lines need to go not only because they are restrictive, but because they will absorb oxygen at the molecular level. That means your boiler water will be oxygenated and that will cause the boiler, iron piping and pumps to rust.

Any nonmetallic piping used in a hydronic system MUST have an O2 barrier. Those hose ain't got it.

FrozenNorth

I'm not sure what to do about those hoses. Do I call the plumber back and tell him to change them? Can he just unscrew them to change them or is it more welding? I wasn't there when he was doing that part of the installation so I don't know what's involved.

The senior plumber is coming Friday to empty the system and fix whatever part is broken. If I got the O2 barrier flexible pipes (like oxygen barrier Pex tubing??) could he install it easily or would it be starting all over and he'd have to bring welding equipment etc? Or is it copper or nothing?

How much misery would leaving these pipes involve and how fast? My boiler is more than 15 years old so I guess sometime in the next five years I'll have to replace it. However, the iron pipes are likely close to 100 years old (house is 1920) and the pipes are not very accessible so if they were to start leaking that would be a major problem.

Thank you for any advice! I am really not sure what to do.

STEVEusaPA

O2 barrier pex would be better than the flex crap, and easier then copper. You shouldn't have to debate this with the 'professional' licensed plumber.

Leon82

He should be able to use the proper pex or copper and still make the connection. He should cut the floor or at least drill a hole so he can run 2 nipples thru.
Then the pex or copper can be installed where there is room in the joist area.

And depending how it is run reducing to 1/2 or those tiny hoses is probably not a good idea

if you leave it there will be 5 years of extra gunk in the pipes that will run thru your new boiler unless they take the time to clean it

Larry Weingarten

Hello, How about using corrugated copper or stainless connectors, like water heaters have?

Yours, Larry

KC_Jones

STEVEusaPA said:

O2 barrier pex would be better than the flex crap, and easier then copper. You shouldn't have to debate this with the 'professional' licensed plumber.

This X100.

You don't have a professional you have a hack. Personally I would cut my losses and find someone who actually knows what they are doing.

Those hoses at most are for hooking up a toilet or a washing machine. They are not designed nor intended to be used on a heating system, this isn't really debatable. It's wrong and there aren't any arguments otherwise.

FrozenNorth

Hi Everyone,

The master plumber came Friday, emptied the system and found the problem to be the circulating pump. He replaced it and the system is working.

I asked him to look at the flex hoses put in by the other plumber and told him that people on this site said they needed to be oxygen impermeable because oxygen would rust the components. He replied "that's true. They're the wrong kind. They're incompatible with the system and they're too small. The radiator is also incompatible" because it requires 200F in the pipes and our system runs at 140F. So he said it would maybe perform at 20% of what it should. But just last week he looked at the job and told me that the previous plumber had done an OK job and the only problem was that the radiator would be slow to warm up! (?!?)

He couldn't replace the flex pipes because he didn't have the time, so he closed the valves to the radiator.

At this point, we're thinking we'll just cut our losses and if it's too cold in February we'll put an electric space-heater in there (it is vented at the front and underneath now) so we can end our interactions with the general contractor and his substandard subcontractors.

Next year we could see if we could find someone good who could tell us what is actually possible, although finding someone good is harder than we thought :-(.

Thank you, all of you, for providing the information I needed. If you hadn't, I don't think anyone locally would have.

Leon82

140 seems low for an iron boiler. That would be very close to the condensation point. Observe it when it runs and see what the temp is.

I would try to Find some one willing to remove a little more of the floor and repipe it with either barrier pex or copper before you abandon it

Leon82

If you give the model of the new radiator some one here can probably tell you how much heat you will get from it at your temp.

But 140/200 would be 70% of the heat not 20