Can a Burnham V8 oil handle Cold Start

Hey_Obie

I have a Burnham V8 3 with tankless hot water. I have added an indirect and want to change the current controls out so that I can add a Cold Start controller and disable the tankless.



I have seem bits a pieces over the past year that leads to to believe that I may have a problem trying to work this boiler from a cold start. Condensation, something about the nipples rusting. I guess if the boiler stays at 150 or so, the boiler can't rust. At zero, to 100, it can rust.



Anyone think I am fine doing this? Or should I not do it?



Thanks in advance,



Mike

icesailor

Can a Burnham handle a cold start?

Maybe yes, maybe no. However,

I know that the rage is cold start. In my personal opinion from vast experience, it is the stupidest idea ever fostered on the industry. I've seen more failed boilers from being plugged up with this cementous material from cold combustion that ends up pushing the boiler sections apart. It is maybe what caused these Burnham boilers apart.

When I clean a "pin" boiler that is a cold start, after a year, it is almost plugged with this cementous material that I scrape out with a soot saw and a piece of 1/4" threaded. Then sucking the crud out of the bottom. It is as hard as a tar road. The warm start on the other hand has all the stuff fall off with the same soot saw and I can actually go for a few years before a major cleaning but the boiler has never plugged up.

If you converted a system with a tankless, wire the Taco controller to the ZC/ZR terminals and have the low limit circulator part of the control run the Taco box.

There is a major difference in the combustion residue from cold start and warm start. Cold start seems to be incomplete combustion. Warm start seems to be just ash.

Don't cap the tankless. It's a waste of time.

I have never installed an indirect on a old system renovation. I've never been able to sell a indirect to a customer because of the work of getting in to the heat system. With a tankless only, and a complaint of lack of hot water, I sell them a 50 gallon electric hot water heater and use it as a storage tank. I don't need to do any wiring except for a plug to run the 006 bronze circulator. It's a lot easier to sell this using what they have and adding a storage tank than the complex indirect.

If anyone wants to know how, ask.

Hey_Obie

Icesailor is on the money

Icesailor,



The only reason I want a cold start is to make the indirect efficient in the summer. I don't like running a 100,000 btu oil boiler in the summer for domestic hot water. It would be nice for it to heat the water and go to sleep. But I hear what you are saying and I believe you 100%



Do you tell your customers to turn off the boiler in the summer and use the electric hot water tank

Robert O'Brien

I disagree

I would use an indirect and either a Beckett AquaSmart or HW AquaReset control. You can try cold start,which with an indirect,really isn't cold start. There is usually a DHW call before the boiler gets to ambient. If needed, you can maintain a reduced low limit to just keep the boiler warm. The bigger question is,why have a boiler that requires that it be kept idling 24/7/365?  The even bigger question is why are single pass pin types still the vast majority of of oil boilers sold?

Hey_Obie

Interesting how I got here

In the spring, I decided to replace the HB Smith boiler that has been in my house for the 23 years I have been here. And it didn't look new back then. It had a Net rating of 150.



I busted the one big zone into two, added a TT indirect and added the Taco ZVC406 (plan on adding radiant to a couple rooms) zone valves and a new Wilo variable speed circulator. Got it all working



Did a heat loss calc and came up with 85,000. So went around and around deciding what boiler to get and came down to the Buderus or Biasi.



So I am getting ready to buy the Biasi, and I get a call from one of my contractor buddies who is renovating a house and they are removing a 5 year old Burnham V8 3 and says I can have it for free if I come and get it.



So pay $2000 for the best solution or $100 (I replaced a few parts) for the older technology. Since I am not working right now, I went with the $100 solution.



I wanted to do it right, but I went most cost effective for the short run.



HOW LOW would you set the lower limit? 120?

Bob Bona_4

disagree

My experience has been that cold start boilers run enough with an indirect to keep them dry inside. The key is properly sized and installed units.

TonyS

Hey Obie

With an Aquasmart you will be able to go from cold start to low minimum with a push of a button. Try it both ways. As far as cleaning goes, leave access to the side entry and you can water clean that boiler in a snap.

Hey_Obie

Bought it

Just ordered the AquaSmart. Thanks

icesailor

Tankless/Indirect

Here's the deal.

If I find a customer who has a tankless and is having hot water quantity problems, and I sense that they will not spring for a complete new system, I sell them a upgrade. A hot water storage tank. I use a 50 gallon electric hot water because it is the cheapest insulated water heater you can buy. A fraction of the cost of a indirect. A tankless is a heat transfer coil. There is no wiring connection through the boiler control circuit. he boiler. A indirect is a storage tank with a tankless coil in the tank. In my opinion. A electric hot water heater is heavily insulated and pre-wired electrically. The only electrical part of the heater I use is the bottom theromstat as a switch leg for the pump. 115 volt. Feed the water heater as you would if it was connected electrically. Take the bottom drain out and add a 6" X3/4" brass nipple and add a drain and a 006 bronze circulator, pumping out of the tank and into the inlet side of the tankless. The outlet is piped into the cold water inlet of the water heater. You need a check valve in the circuit. It can be 1/2" tube. There is no pressure drop through the coil because the cold is in and out of the hot water tank.

With the triple acting thermostat and the operating tempreture set at 140', you have a warm start boiler. If there is a call for heat, the boiler goes up to high limit. If the domestic hot water pump starts to make hot water, the temp around the coil starts the boiler to operate on the low limit setting.

I won't say that I have done hundreds of these, but I've done more than 50. I've done this since 1976 when I decided that aqua booster heaters were overpriced and didn't work well.

To make it work, you only need a cord whip to run the circulator and run a switch leg through the bottom thermostat. On gas boilers, I use indirects.

It's cheap to install, and cheap to run. It will never run on high limit during the summer unless I turn up a heating zone.

I've installed Bock 73E 220 GPH recovery water heaters into 100 gallon storage tanks using this piping arrangement to pick up the slack in certain commercial applications where they have quick imtermitant draws. It works.  

Hey_Obie

I wish I had seen this before I bought my indirect

On my old system, I did something similar, but much less sophisticated. The old unit had a tankless. What I did was use the tankless to feed the electric hot water heater on the cold side. The electric hot water heater (80gal and not a little 30 indirect) was a storage tank that could also keep the water hot warm using electric if it needed it (but I don't think the electric ran very often). So I dumped the 150 degree water into the electric tank and let the mixing valve do its job. It was a great system.



In the summer, I shut down the boiler (it was too big and old for HW only) and went electric. It was simple and worked beautifully.



I think it was a better idea than an indirect. If I had to do it over again, I would have kept my old design and kept my $900 that I spent on an indirect which I will never recoup. When this indirect goes out, I will reconnect my tankless (I disabled it) and remove the indirect.