Gravity hot water question

STEAM DOCTOR

Hi to all. Need some advice. I have a customer with a converted gravity hot water system. Massive mains and massive cast iron radiators. Lots and lots of return water. Current boiler is a fairly new cast iron boiler with no means of protection against low returns Temps. Repiping would be costly. Was thinking of using the Taco Veridian vt2218 circulator and have it set up in the boiler protection mode. My main concern is the fact that the the return May take forever 2 reach acceptable Temps. The circulator will run slower until the return Temps are acceptable. I am concerned that the home may never heat properly if the circulator is running slow for a very very long time. Please advise. Thank you so much. I know ideally it should have some sort of bypass valve but not sure if that's a viable option at this stage in the game.

DanHolohan

I believe you need relatively high flow against almost no head resistance, and a bypass is the traditional way of dealing with the low-return temperature.

STEAM DOCTOR

@Dan Holohan. Thanks. I am well aware. I have read and studied just about all of your works. There is currently no bypass and piping one in would be quite an ordeal. I am just wondering if the Veridian would be a viable option. Thanks again for your advice on this topic and so much more

DanHolohan

Thanks. Would it give you high flow against hardly any head? Let's hear what the others have to say.

STEAM DOCTOR

I'm not really that worried about the high flow. They are currently pumping with a 007. They say everything is heating up adequately. I am more concerned about the low flow of the Veridian when return temperatures are low

DanHolohan

Yes to what you say. And the traditional circulator for this was the B&G Series 100 or the Taco 110. Both have the proper curve, as does the Taco 0010

STEAM DOCTOR

@Dan Holohan. Yes that veridian is good option or yes that i should be concerned about low speeds? Thanks again for taking your time and sharing your expertise.

ratio

Maybe a pair of saddle taps could give you a bypass without significant repiping?

JUGHNE

Piping picture?

DanHolohan

@STEAM DOCTOR Yes, I'd be concerned about low flow.

bob eck

If you have black steel pipe on the supply and return you might be able to have a contractor cut into the steel pipe and they could install Viega Megapress tees that press directly onto the steel pipe and then run a bypass. No need to thread the steel pipe that is cut. What size is the supply and return pipe? Viega has up to 2” Megapress fittings and they are coming out with 2 1/2” - 3” - 4” Megapress fittings early this year. Viega makes a Megapress tee that is press x press x FIP and then the contractor could do the bypass in copper tubing.

STEAM DOCTOR

@bobeck. I am able to do the piping myself. Looking to make this a painless as possible for the homeowner. Will probably take a few hours just to drain and bleed the system

bob eck

What size is the pipe?

STEAM DOCTOR

Boiler piping to mains is inch and a quarter. Mains themselves are 3 or 4 inch. Don't remember off the top of my head. I was there the other day for something else and noticed that they were lacking boiler protection

EBEBRATT-Ed

I like the saddle tap idea that @ratio mentioned. I was thinking the same but he beat me to it!! You can buy and install saddle taps and hot tap the system but if you don't have the hot tap equipment it's probably cost prohibitive.

But, you could drain the system and install a couple of Victaulic 920 mechanical tees. Just hole saw the pipe and bolt them on with a couple of valves. You can be filling the system while you pipe the bypass. Probably the best option.

Mega press says their coming out with fittings larger than 2" been hearing that for a while. But the you have to have the mega press jaws and a pro press machine.

STEAM DOCTOR

Don't have the equipment. Again it's well within my ability to repipe. will be quite expensive for the homeowner. With three or four inch mains Plus somewhere in the vicinity of 20 very large column radiators you're talking a good few hours just to drain and Purge. Some of those radiators are in enclosures that will be a bear to remove. If simply replacing the circulator is a viable solution then that is the approach that is probably most sensible. Just would like to get other opinions about the viability of using the Veridian for this application. Thanks

bob eck

Steam Doctor where are you located? I work for F W Webb in Allentown PA and we rent the Ridgid progress tool and Megapress jaws to local professional contractors in the Allentown PA area. I believe other wholesalers might also rent these tools.

DanHolohan

I think you need the bypass.

JUGHNE

If you replace the circulator won't you have to drain and refill?
I have had to do that a couple of times and the first chance I made sure to add isolation valves for boiler/pump/anything service.
We are talking only 1 1/4" valves. And then a couple of tees for the bypass setup.
If the homeowner was aware of the time required to even check the air in expansion tank etc. he might consider the valves a good investment. (of course they could be added later when the boiler rusts out from condensation).