Runtal panel radiators

tim smith

Just my feelings but I have seen steel Buderus panels rust out on jobs by others. The Runtals are made of thicker steel which is why I prefer them but of course they are more expensive. I have had a cut away section of Runtal before and they definately are fairly meaty. I think probably 1/16" + steel tube appx. Maybe the amount of tube left on system when you are done won't be that much and this would prevent oxygen damage but I am a little skittish. Tim

Joe_142

Runtal panel radiators

Are the interior surfaces of those radiators prepared with anything to prevent corrosion when they're used in a closed hydronic system, or is there any risk?

I take it for granted that they are steel and not some non-ferrous material. Wonder what gauge of sheet metal they use.

I had been looking at them on their website and got to wondering about that. Right now, I use copper finned tube baseboard for heating and thought those Runtal units looked appealing but shudder at the thought of one rusting out some year in the future.

I did a search on runtal and didn't see anyone ever ask that question.

kpc_52

They are steel....

but in a CLOSED system they will be fine. I just re did a boiler that had Runtals in w/ non barrier tubing... it let in O2 over a lond period of time and it did ruin 1 panel rad. I have Buderus panel rads in my home and have barrier tubing... no issues. This is the primary radiator in Europe.

Mark Eatherton

Corrosion inhibitors not recommended...

I remember reading in an RPA document that the use of corrosion inhibitors is not recommended in systems using thin steel panel radiators because of the possibility of bubbles, not allowing complete coating and coverage by the inhibitors, then when that part of the panel does get whetted, corrosion would occur at an accelerated pace due to the lack of coverage/coating.

Personally, I have thousands of thin panel radiators out there and have only had issues with one system that had glycol in it. The glycol went acidic due to leaking relief valve and inadvertent dillution, and the radiators started pin holeing.

If you have a tight, oxygen free system, it should not be a problem. If you are concerned with electrolysis, use some sort of brass fitting between the copper distribution system and its connections to the steel panel radiators, and you will be fine.

ME

kpc_52

really...

so let me run this one by you Mark. This system has home runs in poly-butylene to each panel rad... no O2 barrier. Unless I re run each run and that means a lot of plaster and drywall... I can't put a HX on each panel rad.... Other that Rohmar 922 what am I to do? kpc

Joe_142

Thanks for the replies.

kpc_52

The system...

was installed in the mid 80's. Wirsbo pPex in the slab, runtal rads on second floor. maniflod ran 1/2" PB w/o O2 barrier and a Glow core!
This is the second boiler replacement. The panel rads for the most part are ok ....minus 1. The boiler is a Embassy ONEX... very cool. To keep the panel rads from further falling apart I cleaned and flushed the system then added Rhomar 922. to keep the boiler and system ok... I will do this every year. To protect the rads I can't place a HX and a circ on evry rad... there are 12. enless I would totaly gut the house what am i to do.

Mark Eatherton

Do this...

Maintain a system pH of around 8.5, the ideal pH range for ferrous components. I'd also induce some oxygen scavenger, and keep your operating temperatures as low as possible to avoid oxygen diffusion.

If your radiators were exposed to the O2 before the Protek, they have already set a protective patina, and the inhibitors probably won't negatively affect it at this point in time.

Just keep an eye on it...

ME

Charlie from wmass

Just make sure they do not get banged around. This has been my only issue with them and they leaked as soon as they were installed. Also use the proper fitting for attaching them. I have seen too many around here where 1/2" Pex by MPT adapters were forced int the rads with copious ammounts of pipe dope and teflon tape. It makes it hard to remove them when they need to be taken out. Also that dark stain on the floors under them bothers me a bit.

kpc_52

thanks...

I also added 3 new circs... all of them bronze.