baseboard heat question

Andre_2 · January 2005

I have 3 zones of hotwater baseboard heat by oil. The third zone was recently installed in my basement. Shortly after being installed, my 2nd floor zone started banging (loudly) when the heat shuts off. Now, after the new zone has been working for a month, it suddenly stopped heating (in addition to the banging on the other zone).

My furnace is Weil McLain. I have a water pressure booster that has been installed for more than a year -- the pressure is set to 60 psi and I've never had a problem with it before, but I'm wondering if the pressure is suddenly too high for the heating system.

Regarding the new zone heat problem, I have checked the motorized valve (which is a Honeywell) and it appears to work correctly -- the thermostat turns the heat on in that zone and the switch activates. However, the hot water doesn't flow through the system. I have also tried the manual override switch with zero effect.

I don't know how to bleed the system -- on what I think is the return side of each zone, I have a spigot, followed by a shut off valve. I have tried opening the spigot and I get plenty of hot water with no air bubbles. I don't know if I'm doing the right thing.

Regarding the banging pipes, I really can't figure it out -- the pipes bang in different locations every time, so it's very hard to locate. The first time I heard it, it woke me up in the middle of the night -- it sounded like an intruder dropping something. there were 5 or 6 bangs. It sounded like it was coming from my bedroom floor. Since then, the banging has traveled around the house.

I'm waiting for my plumber to come back and fix the problem, but the first time he arrived he couldn't hear any banging. Since then, the banging has become very reliable and I'm sure I can reproduce it. However, I'd like to know possible causes and fixes -- I've been waiting over a week for the plumber to show and I feel completely helpless.

Thanks in advance.

Weezbo · January 2005

Your mistaken,the pressure is more likely much less ...

there may be a temp pressure and it look like it is 60 psi,however that gauge is like a two dollar watch that isnt running or perhaps not even that good...the banging is likely the zone valve is upside down or doesnt have the same flow rate as an extremely over sized pump.looking at it it may have an arrow on the valve body, thats the direction of flow...the chance yor able to do any thing to the system without tools is remote,however, do this....go to the valve and manually open it and lock it open for an hour. see you then...

Dale · January 2005

Banging

This (banging) is usually from a zone valve being installed backwards or too much pump for the correctly installed zone valve. Did you change the pump when you did the addition? Is the addition much smaller than the other zones? The banging can also be from a pipe that's not allowed to expand, you may want to check all holes and pipe hangers. The pressure booster should be only on the domestic hot water and in no way connected to the boiler. You should have about 12# in the boiler when it's cold.

Andre_2 · January 2005

Weezbo,

Thanks for your reply, but I think you may have missed a few things in my previous post.

The water pressure pump is reliably 60 psi -- this is not the pressure gauge on the furnace. We have low water pressure (we are at the end of the line on the top of a hill) so we had the booster pump installed last year. The pressure booster never impacted the heat before. I don't know what the pressure on the furnace is, but the water pressure in the house is definitely at or near 60 psi.

Also, the valves are in the correct direction -- the older zones have been in operation for 4 years without a problem, and I verified that the new valve is in fact in the right direction.

I manually opened the new zone (as I mentioned in my earlier post) for several hours and still did not get any heat in the new zone.

Regarding the banging, I will try the "spring" technique mentioned on this board, but logically, it doesn't seem like that could be the cause since it never caused a problem before. I keep coming back to the idea that the new zone must have something to do with the banging.

Andre_2 · January 2005

Dale,

The pressure booster is at the water main pipe that comes into the house. I don't know much about heating, but I always assumed that the water main eventually connects to the heating system, and that therefore the pressure booster can have some effect on the heat. Is that not true? In any case, I doubt the pressure booster could be the cause of this since it has never been a problem before, but I thought I would mention it just in case.

Uni R · January 2005

Domestic Water - Boiler Water

The domestic water is only connected to do the initial system fill. It usually comes into the boiler system from a pressure reducing valve that only lets water through if the pressure in the boiler system is less than 12 psi. It also has a shutoff valve and that is often closed and definitely should be closed if your boiler has a low water cutoff (LWCO). The boiler system is just like the coolant system in your car. If you have to start adding collant (or in this case make up water) then you have a problem. Hope that helps...

Your system pressure probably should be about 12 psi cold and maybe into the low 20s when the system is at its hottest temps.

Andre_2 · January 2005

Thanks Uni. I guess that takes the water pressure booster out of the equation.

Any ideas what could be causing this?

Weezbo · January 2005

if the water pump IS connected to the boiler ...

there needs to be a check valve,back flow preventor and fast fill on the "automatic" feed water supply to the boiler............then, open the zone valve manually,close all the others,let it run a while................if the boiler feed water supply is set and functioning correctly it will maintain the pressure as the air is entrained in the system and eliminated at the spirovent.........if you do not have a spirovent and there are no baseboard "T"'s to manually beed the air from the system then.......it is easy enough to determine..............and what to do next. its been an hour....is it functioning?.........if i had a picture it might help.............here is something else you can do get a washing machine hose,turn the boiler off.....close th ball valve on all the zones except the supply and return on the boiler.....get a bucket,put a gallon of water in it,connect the hose to the "Purge" valve put the other end of the hose in the bucket under the water....open the feed water valve to the system and the corresponding valve to the base board looplet the water pressure build up in the boiler about 7->8 more poundsopen the purge valve handel, when the bubbles stop comming out of the surface of the water,close it down to a slow trickel until hot water is comming out of the hose..then shut the valve....disconnet the hose.........turn the boiler back on,...run That zone (open the zone valveand both the supply and return to only that zone......let it run for an hour..........any sounds of hammering? i will be here.......

TTI Inc. · January 2005

Banging

Just another though about this problem, banging in a hydronic system is sometimes caused by a lack of expansion room in the system piping and boiler. I would shut down the boiler, close the make up water supply valve and drain the expansion tank fully. Open the make up supply valve and restart boiler. Normal operating pressur should be 12 PSI or slighly more when hot.

CLC · January 2005

baseboard heat problems

It sounds like the banging noise could be the result of a few factors, which may or may not be directly related to your lack of heat in the affected zone. Many times an air lock is the culprit. If this is the case you need to get rid of the air from the system, a transfer pump is usually ideal. If you have bleeder valves on your upper baseboard zones, they will help to eliminate the air. If not try to purge individual zones (and runs) one at a time. This will prevent air from migrating from one zone to another. If the pump is moving that air around from one side of the zone(s) to the other, a slug of water hitting a 90 or other change of pipe direction, banging will be heard, especially if the pump is too big and fluid is moving fast.

You say the zone valve appears to be operating properly. Is the end switch really calling the boiler and/or pump? Those motorized Honeywell zone valves have a microswitch that not uncommonly go bad. The valve will open, but not tell the boiler/pump to turn on. Make sure it is actually calling.

Once the call for heat is ended, the Honeywell motorized zone valve shuts down pretty quick. If the fluid velocity is high, a banging noise can sometimes occur due to the sudden closure. Depending on the size of the pump and heating system, a differential pressure bypass valve can help prevent this sudden fluid "brake".

I have also seen the zone valve gears become worn and stripped and not actually open the valve. Also, make sure the internal guts of the valve are still intact. I've seen the rubber seal, gasket, etc. actually break or fall of and plug the valve. Good Luck!

Uni R · January 2005

TTI

He may have a bladder type tank.

Andre_2 · January 2005

You guys are getting a bit too technical for me to follow. I don't know if I have a bladder system -- how can I tell?

here's what I have--

Going into the furnace (on the return side), I have one line that branches off to 3 zones. Each zone has it's own spigot and shutoff valve.

On the supply side of the heat, I also have 3 branches. Each has a motorized Honeywell valve.

There's a grey tank mounted to the ceiling (some sort of storage tank or overflow tank).

Regarding the pressure on the furnace gauge, it reads 4psi. There's a red arrow on the gauge around 12psi -- my actual pressure seems much lower than that. If my pressure is supposed to be 12psi, how do I adjust it?

I don't know what a spirovent is.

On the cold zone, I do have hot water running from the spigot with no air (as far as I can tell), yet I don't have hot baseboards. How do I accurately test this? Do I shut off the valves for all zones (except the zone in question) and then open the spigot?

Uni R · January 2005

Add water!!! The grey tank is...

4psi??? You have insufficient water pressure! You should get someone out to look at it and carefully show you the components.

As for the air tank. Is it a big cylinder between the joists or does it look more like a small BBQ propane cylinder with water going in one end and a little air valve nipple at the other end? The big cylinder is a conventional tank. The BBQ style tank is a bladder tank.

A Spirovent is a device that helps any trapped air escape to the atmoshere. Often you see a bladder type tank hanging below it. Sprirovents aren't used with conventional style tanks.

Andre_2 · January 2005

I have the grey cylinder. What is it for? It has a spigot on one end. I've never touched it since I've been in the house.

What would cause low pressure in the furnace? I recently had someone from our oil company out to clean and inspect the furnace and he bled the lines while he was here. He said the furnace was in great shape. I had the service done because I have been finishing my basement (the reason for the new 3rd zone) and a lot of dust got all over the furnace. I wanted to have it cleaned before the really cold weather started.

Also, could low pressure cause the banging?

Andre_2 · January 2005

I have the grey cylinder. What is it for? It has a spigot on one end. I've never touched it since I've been in the house.

What would cause low pressure in the furnace? I recently had someone from our oil company out to clean and inspect the furnace and he bled the lines while he was here. He said the furnace was in great shape. I had the service done because I have been finishing my basement (the reason for the new 3rd zone) and a lot of dust got all over the furnace. I wanted to have it cleaned before the really cold weather started.

Also, could low pressure cause the banging?

Weezbo · January 2005

Andre ,...Take a picture and send it to me e-mail

or post it.as a jpeg..Trust what i am saying to you. Turn the valves off, on the returns,turn the boiler Off.get a washing machine hose and connect it to the spigot of the zone in question.get a bucket, put a gallon of water in it,open the boiler fast fill valve,add about 7->8 pounds of water,put the hose in the bucket so the end of it under water, crack open that spigot and when the bubbles quit comming out the zone is purged....then run the pressure up 7 or 8 pounds ,turn the boiler back on and let that zone run an hour...i will be here..... since this started i have already run did about the same thing and lined out a job for a three way motorized modulating mixing valve...trust some body...every one is telling you basically the same thing here.

Uni R · January 2005

Yes

The low pressure is a very likely cause for the banging. Water boils at a higher temperature under pressure. Under low pressure it can flash to steam. Also, the heating circulators work better with a proper level of pressure.

Andre_2 · January 2005

Thanks Uni. I'll have the plumber check that whenever he shows up.

Weezbo · January 2005

well Andre..whats it going to be?

call a pro or meander around aimlessly for another day ?it isnt going to fix itself some one has to purge the system correctly the first time, minimum.it is hard to understand what we take for granted as we use words that you dont have a picture for in your minds eye,that isnt a crime or a sign that you arent smart or anything else however as it is now daylight is burning and it needs to be fixed .so call some one . your boiler is ketteling and it is only going to become more and more expensive to repair by waiting around for days...i am here for another hour after which i am out and about...try the washing machine hose it is about as simple a way to get it purged as i know.

Andre_2 · January 2005

Weezbo,

Thanks for your offers to help. I'm having trouble believing that 2 people (our plumber and an oil co. rep) incorrectly bled the lines. True, it's possible, but how likely is it? I don't know how to adjust the water pressure on my furnace, which Uni seems to think could be the cause of this. Therefore, I'll wait for the plumber.

Weezbo · January 2005

ok. it very well could be a leak on that zone .

and that be the cause.

Andre_2 · January 2005

The basement heat pipe was frozen in one section -- this was the cause for no heat in zone 3. As I mentioned, this zone is in the basement, and apparently one small area was not insulated very well before we sheetrocked the walls. The plumber has offered to add anti-freeze to all zones, at a cost of approx $400. Does this sound reasonable?

They will research the banging on the other zones next, but they believe it is related to the frozen pipe.

By the way -- they used some kind of black rubber tubing for the heat in zone 3, instead of copper pipes. The rubber tubing runs through the walls, and then where it pops out for the basement, they used copper pipe. I have not seen the rubber tubing used before, but they say it's no different than using copper pipe.

baseboard heat question

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