Basement radiator does not heat after boiler changed

Yoshimura

I have two basement radiators in a single zone hot water system with cast iron radiators and a new Bosch Greenstar combi boiler. The first smaller basement radiator (also piped by overhead piping) takes off right after the boiler and gets warm fine. The second significantly larger radiator used to heat up fine with my old boiler (Knight), but after that was flooded by Sandy, and was replaced with the Bosch combi, doesn't heat it any more. The piping that takes off from the main supply and return lines is above the radiator (note this was fine with the old install). The piping is warm up to a point and then cold. When I bleed the radiator cold water comes out, no air. The combi has its own circulator and an additional one that was added by the installer (Rapid Repair NYC) both on the return lines. The upstairs radiators heat very well. I suspect air in the pipe above the radiator. Apart from draining the system and adding the bleeder, is there another way around this? I've been running the boiler hot and also tried increasing pressure until the PRV released it. Any other information that would help sort this out? Thanks in advance for your help!!

Ironman

Pics?

Some pics of the rad, its Tees and near boiler piping would be very helpful.

Is this a mono flo system? Cast iron rads?

It's most likely air which can be difficult to bleed on some systems. Your installer should take care of this.

Yoshimura

Result of a little experiment right after I posted the question

There are ball valves on the supply and return piping near this cast iron radiator. I turned off one of them at a time and bled the radiator. Hot water does move into the pipes all the way to the radiator when you do this. So doesn't seem (IMHO) like air. Is the pump not adequate? The pump configuration is different this time around. Will try to get Rapid Repair back in to check, if possible.

Yoshimura

Tried posting pics, must be doing something wrong

Can I upload from my smartphone or do they need to be on a shared site like Phoobucket, etc.

Ironman

Not Sure

You should be able to upload from your phone, but there may be limitations as to the file types that would be accepted.

Yoshimura

Trying pics again

Trying pics again

Yoshimura

Pics successfully posted

Here are some pics

CMadatMe

Manual

Is pretty blank of information but I don't see primary/secondary piping here. Are you sure it's not that the system side flow rate needs more then the boiler can provide?



The manual is here and they don't even given you boiler head pressure.



http://www.bosch-climate.us/files/201106211629070.6720643068_Bosch%20Greenstar%20Boiler-ISM.pdf

Yoshimura

Primary Secondary piping

Right under the boiler (you can see it in the pic) is a connection between the supply and return piping. Is that what you mean by primary secondary piping?

CMadatMe

Pri/Sec

There are suppose to be two closely space tee's where the boiler supply and return enter the system loop similar to the attached

Yoshimura

Monoflo and closely spaced tees

This system has separate supply and return piping, i.e. the rads supply and returns take off from separate pipes in the basement. The length of pipe with the yellow handle ball valve in the photo looks like it connects the supply and return tees. Does this help? All radiators including the first one in the basement heat well, except the one in the pic (which is the second radiator to take off after the boiler).

Thanks for your help!

Yoshimura

How about forced-water purging as described here

http://books.google.com/books?id=WdPg_1aTtr8C&pg=PA483&lpg=PA483&dq=forced+water+purging+hydronic+system&source=bl&ots=0cOi8jihYK&sig=dy3_KwjZXM6lbm89wPi5b5BfpY0&hl=en&sa=X&ei=CxAHUfPRIazK0AHevoDYDQ&ved=0CDoQ6AEwAQ#v=onepage&q=forced%20water%20purging%20hydronic%20system&f=false

kcopp

thats a bypass...

not primary secondary... You need 1 for the boiler loop and 2nd for the system. The system pump should also be piped in after the extrol tank.  Whey wsn't the FW200 control that came w/ the boiler installed? With all that cast iron radiation it is an ideal match.... Not sure why that swing check valve is in there. I have installed 2 combi's and 1 heat only. pretty decent units.

I see a heat gun on the rad... did the pipe freeze?

Paul48

Look

Look at page 54. That's as close as they get to a piping diagram. The piping needs to be corrected.

Alan (California Radiant) Forbes

If you can,

turn off as many of the other radiators as possible. The more you can turn off, the more pump head you can dedicate to pushing any air out.

Yoshimura

FW200 is installed remotely

It's upstairs where the thermostat used to be.

I was trying to heat out the air in the pipes with the heat gun (the pipes did not freeze). Would the absence of primary secondary and the pump location affect the basement radiator not heating?

I did try to purge the radiator after increasing the system pressure to over 50 psi with the fill valve and closing the ball valves on the supply and return lines to the boiler. Don't think it worked.

Is the problem an air lock or is there not enough pump pressure to circulate water through the basement radiator due to the pump (Taco 007-F5) location on the return?

Thanks again for helping me through this.

CMadatMe

Boiler Has It's Own Pump

And the boiler is pipe wrong period. Never knew heating up a pipe could remove air. Learned something new. Need to pipe pri/sec and move that 007 after the spirovent pumping through the rads not away from them. Also need to make sure that 007 is even the right pump.

Ironman

Piped Wrong

The boiler should be piped pri/sec as per page 34 of the applications manual. It also should NOT have a bypass. No mod/con should have a bypass. Close it off for now and you may get some heat out of that rad, but the near boiler piping must be corrected.



The boiler has an internal circ which is good for about 4.5 gpm. The way it's piped now, the external circ is in series with the boiler circ. It also needs to be positioned with the shaft horizontal, not vertical as it is now.



The installer did a neat job, but it appears he was lacking in knowledge about mod/cons.



Fellas, Bosch and Buderus provide applications manuals that give extensive piping, wiring and control diagrams. Much more in them than the average I&O manual.

Paul48

Bob

Are those in the document package supplied with the boiler?

Steve Whitbeck

Piping

Because the piping is wrong You are not getting enough water flow to satisfy all of the radiators at once. Water is flowing to the ones with the least resistance and HOT water doesn't like to go down. Increase the water flow and your problem will go away.

Not a good choice for a replacement. WHN Knight would have been a better choice.

Ironman

Paul...

Buderus used to, don't know if they do now. With all the bean counters that Bosch brought in, there's been a cutback in literature. Can't hardly get many glossy sales brochures anymore. The expect you to get it from the web site.

CMadatMe

Bob Pretty Much

Gave you the entire lay of the land in black and white. Page 34 sums it up in a nutshell. Time to call your installer and have him come back and fix it.



Another sick patient prescribed the proper medication by the doctors at heatinghelp.com.

Yoshimura

Seems to work!?

I turned off all the upstairs rads but one rad (dare not mess with the valve on that, it starts to leak) and I hear water flowing through the supply pipe to the basement rad (and also a bunch of air). Plan to wait for an hour and see if it heats up.

Ironman

Keep on Reading Below

.

CMadatMe

The boiler is Pipe Wrong

All you did was cut down the flow needed for the entire system and forced it into that rad, Once you open them all up again problem will be back.

Paul48

Never Had A Chance

There's so many installers out there that don't have a clue. But, who gets the dirty end of the stick, when you have a 120 page I&O with no piping diagram........the homeowner. I'll bet they didn't even know there was a circ in the boiler.

CMadatMe

Poster Doesn't Want to Hear It

You have everyone telling him what is wrong and he gravitated to what he wanted to hear. You can lead the horse to the troff but we all know what we can't make it do..

Yoshimura

Trying to respond to all your kind comments

Let me put this in context. My Knight WBN 080 was submerged in the salt water of hurricane Sandy when my basement flooded to the ceiling. This new boiler was put in by Rapid Repair NYC which is a program that the city and FEMA put in place to patch us up and give us heat so that we could stay in our homes, which we just got less than a week ago (after using space heaters and wood heat through December and most of January in below freezing temps).

The good heating professionals in NYC were swamped and those that weren't were charging way more than the original installation and piping cost me, just to replace the unit. Many were giving shady deals and all sorts of spiel. With thousands without boilers and hot water, there were few options.

It's true the kind men who installed this boiler hadn't done a mod con before. But, the program allowed them to do a 1:1 replacement only and whatever was available. Hence, wall hung for wall hung, mod con for mod con. And Bosch was what they had. So that's what they gave me. (btw, why is that a bad choice for a replacement?)

When this cold season is over and things cool down a bit, I will consult somebody with mod con expertise to redo some of this and possibly move the boiler upstairs. Our basements will surely get flooded again in the next major hurricane and its not possible to keep replacing boilers. (hence, also can't have a boiler that sits on the floor).

I don't think the original installers have the expertise, besides, since the heat is working, they're most likely fixing up other people who still don't have any and coming back and redoing this install would be a low priority for them.

I will direct whoever comes to correct the situation to the manual and the diagram on pg 34 (which was not provided with the boiler).

In the meantime, this big cast iron radiator heats my basement and I was trying to get it going, doing whatever it took, including heating the pipes with a heat gun. It appears though that the issue lies not with air in the pipes, but as many of you have suggested, with the circulator being in the wrong place. (I agree, the installers didn't seem aware that the boiler had it's own circulator.)

So please bear with me in my situation and thanks again for your help.

kcopp

I did not realize...

that was the combi version... as I did not see a mixing valve on the domestic piping. As to the boiler ,it is a fine unit and it will srve you well. The only drawback I see to it is the hot water output is a little on the low end but if you onlt have 1 bath it is fine.

pipeking

i hope u change it..

  cast iron radiators like slow moving water,and your boilers heat exchanger needs fast moving water. u could very well end up having boiler problems. and i always put a strainer in when retrofiting to cast iron.

Yoshimura

Pipeking, change it?

Pipeking, change the boiler or the circulator / pump location/ primary secondary piping?

I didn't understand right.

RobG

Boiler Bypass

I would say that until the boiler piping is corrected to close that bypass but it might be the only thing protecting the heat exchanger from low flow?

Rob

Yoshimura

Thanks, good to know.

I have it turned off, but will open it again. Like other posters said, the radiator stops heating after you turn the other rads in the house back on. So does seem like the pump or the way it is piped does not have enough pressure.

Alan (California Radiant) Forbes

I Disagree

If you look at page 10 of the instruction manual, there is a list of different systems.  Mr. Yoshimura's contractor chose System 2 as the one that represented his job.  He then turned to page 11 and realized that the pump that came with the boiler may not be large enough, so he added a small one in series to add additional head to make sure the heat exchanger was happy and then piped it according to the diagram on page 18.



Some corrections need to be made:

1) Permanently turn off the bypass

2) Mount the pump horizontally

3) Add a condensate neutralizer

4) Insulate all the piping



While not piped the way you or I would install this system, I don't think we should condemn this layout.

Ironman

Alan...

I have to disagree with your take on this.



Mr. Yoshimura sent me a P.M. this morning and confirmed that the installers had never done a mod/con before his. He also confirmed that the applications manual that I posted did NOT come with the boiler, therefore, they did not have it and your supposition about them piping it from the manual is baseless.



Also, there is no diagram in the manual that shows adding a circ in series with the boiler circ. The manual is clear that if more than 4gpm is needed, then p/s piping is required.



Your kind spirit for the installers is admirable, but you let it lead you away from the facts in this case. I cannot accept that someone who would put a bypass on a mod/con and install a circ shaft up, would have the knowledge to go to an applications manual and calculate system and heat exchanger head and then go to a pump curve and select a 007 to add in series with the boiler circ.



They may have been nice guys, but knowledgeable they weren't.



This is also not an acceptable alternative because that is a combi boiler. If left the way it is, the 007 will deadhead when there's a domestic demand because the internal 3 way valve will shut off flow to the system loop.

Alan (California Radiant) Forbes

Thanks, Ironman

I accept what you say.  After all, my supposition is based on presumption and I don't feel like getting into a shouting match over this.  It won't be hard to correct the piping.



And when the piping is corrected, do you foresee the basement radiator heating up properly?

Steve Whitbeck

P/S piping

Without primary/secondary piping You will never get enough flow to satisfy all of the radiators. Leave the bypass closed. That Taco pump may fail because the top bearing is probably in air not water.

I don't like that style of combi boiler because it doesn't do either job well  and have a short life span, high maintenance.

Ironman

If...

The rad worked before the new boiler was installed, then it should work when the piping is corrected. Assuming all the normal bases are covered.



To me, the sad thing about this install is that it's obvious that the installers tried to do a good job, they just lacked the know how. It's another Sandy replacement. Things are still so hectic that they install any boiler the can get and send any crew to do it even if the don't have the experience or training. The home owner becomes a victim of circumstances.

CMadatMe

Need To

Satisfy required system gpm before any answer to that question Alan. We are all lacking the heat loss as well as existing sqft of edr on the rads. Not even sure that 007 will do it's job as a system pump.

Steve Whitbeck

007

If the 007 isn't big enough the boiler isn't either.

The pump size isn't the problem - the orientation of it and the piping is.

Alan (California Radiant) Forbes

Curious

then as to why one of the closest radiators to the boiler won't heat. It looks like it's a two pipe, direct return system, no? If flow or pressure drop was an issue, you would think that the most remote radiator wouldn't heat.



Y'know, sometimes it's just plain weird why some of this stuff doesn't work. In my next life, I'll be Voodoo Hydronics.