Basement radiator does not heat after boiler changed

Steve Whitbeck

flow

Alan - It is all about flow. The least resistance is getting most of the flow. AND hot water won't go down unless you make it.

Alan (California Radiant) Forbes

Mr. Yoshimura:

Please keep us informed as to the future history of your heating system.  We are VERY interested.  Not to be right; only to learn.

CMadatMe

We Can Assume

I agree the pump may be correct but then again we do not know system head requirements. I pointed out in about the 3rd or 4th post on the thread that this boiler was piped wrong.

Yoshimura

Recent update

First off, let me thank you all for continuing to help me with this issue!



So, as of this morning, the big basement rad does not heat unless you turn off most of the other rads. I also shut off the bypass and pressurized the system to 12 psi. When I do that, I hear what I assume is water start to flow into the pipes (risers to the radiator?) and the radiator heats up slowly and not as much as it did before (and I also hear sloshing and tinkling sounds in the supply (or is it return?) pipe to the radiator which I didn't hear with the old boiler). The small basement rad, that is the first off the system heats fine.



I'd done a heat loss with the Slant Fin software before I got the Knight installed 4 years ago and it was less than 50,000 on design day. I'd also done a spread sheet of all the radiators and their EMDR/ BTU/ surface area, etc. but can't find that today.



Please let me know if I can answer any other questions. Thanks again!

pipeking

I DON'T GET Y?

 if MR. Y had a KNIGHT b4 this 1, it should have ben just a boiler swap with little change to the near boiler pipeing.  MR. Y, when u turn off some off the other rads and get flow threw the 1 thats not heating, u can hear water flowing, right? does it sound like a waterfall? if it is noisey then there is air in the system. a system with no air is very quiet.  this is not the right solution, but for now u can turn up the speed on the circulator inside the boiler.

CMadatMe

If He Had A Knight

Then it was piped primary secondary. He could easily turn off the other rads and get flow through the problem rad. He has already said that. The boiler piping needs to be corrected to make sure he can deliver the proper flow out to the system.

Yoshimura

Piping was changed, the flow is noisy, boiler Grundfos pump already at III

They removed all the old near boiler piping and put in new piping. The old system had three Grundfos pumps (one for the DHW tank) and some elongated red gizmo covered with foam insulation that said Bell Gosset Primary Secondary on it. None of the plumbers could figure out what it was. It's all still lying in my backyard.

The water that I hear flowing makes tinkling noises, more like a stream than a waterfall. But, it's not quiet. To me it sounds like it's flowing around a bubble.

The internal Grundfos circulator was at III when the Bosch combi boiler was installed.

SWEI

elongated red gizmo covered with foam insulation

Was your low loss header.  It's the best way to setup primary/secondary piping in most cases.  http://unitedstates.xylemappliedwater.com/brands/bell-gossett/hydronic-heatingplumbing-accessories/primary-secondary-headers-psh/psh-primary-secondary-header/



If your plumbers couldn't figure out what it was, you need to find a new plumber.

Paul48

Babbling Brook

That is how Taco describes the sound from circulation below 2 ft/s.

Paul48

From Taco

If any [circulator] pump is put in series with another pump, the heads are additive at the same flow. To increase the flow, the [circulator] pumps have to be put in parallel. With pumps in parallel, the flows are additive at the same head. When [circulator] pumps are put in series, install a nipple between 2 flanges. Bolt the discharge of one [circulator] pump to one flange, and the suction of the other [circulator] pump to the other flange."

CMadatMe

It Needs

That is the missing link that needs to be installed. I guess "Rapid" is a nice marketing name but that's about it.

Paul48

Merely

An answer as to why. Not a solution in you case. It must be piped P/S.

Yoshimura

May I ask a question about installs?

I've often seen videos on youtube of installations of this and other combi boilers in UK/ Europe next to regular kitchen cabinets, with supply, return, gas, hot and cold water pipes exiting from the bottom and nothing else.

No external expansion tanks, no external pumps, no extensive near boiler piping, pressure guages, spirovents, etc. etc. Just the boiler and a few pipes.

The Bosch combi for example, contains it's own expansion tank, pressure guage, LWCO, PRV, circulator pump, air eliminator, etc. My house is 1600 sq ft, brick, three stories, attached townhouse. A single zone system with supply return and cast iron rads.

I've heard of these installations in the UK in what they call 'airing cupboards' which I think is a small closet with some ventilation.

So why do most installs I've seen in the US take up all this space? Is it a code thing? Or is it just a carry over of an era of having huge boilers in big basements that had all the room to run piping and attach accessories and zones and pumps and so on. To have redundancy or is it bigger is better kind of thinking?

Please don't take this the wrong way. I'm just curious and also since I want to move this boiler upstairs into my living space. The basement is likely to get flooded in the next hurricane as well.

pipeking

my heart goes out to u

MR.Y. save that beautiful low loss header for the fix!  if it is important for that rad to work, in the mean time till u get the pipeing fixed, i would do this...  turn off all the rads except for 1, then run the system to get the air out. after 10min of the pumps runing, shut that 1 rad off and turn another on, and so on, and so on. until  u have ran every rad by itself for atleast 10min. the spirovent should take all the traped air out. i beleive if it is that noisy then u have air, and if u get ALL the air out, i want to beleive all the rads should heat. also try closing somr of the rad supply valves alittle. this is the best advise i can give u, until u get it repiped. if u choose not to get this boiler piped right (like your knight was) there is a very very good chance of your heat exchanger failing.

CMadatMe

Way Different

The entire systems across the pond are different. We zone, they do not, we install baseboard, the install radiant and panel radiators. Most if not all systems across the pond run on constant circulation.

Paul48

Understandable ???

Your boiler should, and can be installed in such a way to facilitate quick removal.The mod/cons available for the European market are designed specifically for that market.The accomodations tend to be smaller than here in the states. They also include some features that good installers here have been screaming for, for years. We are way behind in the technology.

Paul48

Be Careful

At this point, closing radiator valves may help with system flow, and further restrict flow through the heat exchanger.

Yoshimura

Time frame?

OK. I'm going to get on having someone re-pipe it. Is there a time frame to getting it repiped? I was thinking maybe by the summer. What can I do to minimize damage to the heat exchanger? Open the bypass? Keep it closed? Open all rads?

Yoshimura

thanks pipeking

:-)

pipeking

it won't

damage the heat exchanger cuz, as u said it will increase the system flow, and the way it is pipe the boiler is part of the system loop. the heat exchanger likes lots of moving water and by closing the rads down will increase flow across the ex.

pipeking

MR.Y

 if u go to page 66 of the manual chris posted, it gives u all the service codes. u will find 1 that says "PURRGING FUNCTION" and that goes onto pg.68. what this function will do is turn the pump on (hopefully both) so u can purge out the air like i explained earlier. follow the directions and it will show u how to use the sevice functions. DO THIS WITH THE BYPASS OFF. once you r done purging, i would leave the bypass open, or halfway open. 

pipeking

OMG....

 i was looking at the pics, and the 1 where u can see the condensate drain, IF U LOOK AT IT CLOSE, THEY WRAPED DUCK TAPE AROUND THE PIPE THEN HUNG IT WITH WIRE!!! WHAT THE HELL! there is a differance between not noing better, and plain ol' hack! im sorry MR.Y.

Yoshimura

Purging

OK. Will do.

I think it did the purging on its own for 4 mins when the boiler was commissioned. The manual then said to turn off the valve behind the pump which the separate 'expert' that the installers had called in (since they weren't sure how to do the start up) closed off.

This expert who had worked with Buderus and other mod cons complimented the installation and called it a good job.

Yoshimura

Purging

OK. Will do.

I think it did the purging on its own for 4 mins when the boiler was commissioned. The manual then said to turn off the valve behind the pump which the separate 'expert' that the installers had called in (since they weren't sure how to do the start up) closed off.

This expert who had worked with Buderus and other mod cons complimented the installation and called it a good job.

Paul48

Sorry

I meant it might help with system flow as it relates to that radiator that is not getting hot. The water is taking the path of least resistance. If you force it to take another path, you will reduce flow through the heat exchanger.

Yoshimura

She is Hot !!!

Since yesterday, the basement radiator has been heating again!



There are no more noises, the system is silent. Both risers to the radiator are hot. All other radiators are ON. I didn't do anything other than turn off as many other rads as I could for a day.

Yoshimura

Thanks for your help everyone!!

Got some very useful knowledge and suggestions.