Converting from steam to hot water

Rodney Summers

My question is -- When does it make sense to convert from steam to hot water?

My home (5 stories incl. basement) has a 7 year old 15.7 H.P. Weil-McLain LGB-6 gas boiler. This boiler sends steam through a two-pipe system with the receiver vent as the only vent. With exception of cast iron in our basement, our radiators are convectors from around 1950.

I have been told that converting to hot water would result in lower gas fuel bills and that it would somehow be possible to zone the system without putting additional risers. If this is possible from a technical point of view, wouldn't the cost of conversion be huge compared to fuel savings? In considering this question, please also note that I have to install a new boiler feeder. If you're wondering why, it's because our condensate unit's pump just failed and I have just realized that:

1. the condensate unit was only 14 gal. versus the minimum 19 specified by Weil-McLain

2. the condensate unit's pump was rated at 18 gpm versus 2.1 as specified by Weil-McLain.

Items 1 and 2 explain why our boiler always seemed to either run low on water or over-fill due to use of a Hydrolevel automatic fresh water make-up unit.

Your advice appreciated.

Steamhead (in transit)

> My question is -- When does it make sense to

> convert from steam to hot water?

>

> My home (5

> stories incl. basement) has a 7 year old 15.7

> H.P. Weil-McLain LGB-6 gas boiler. This boiler

> sends steam through a two-pipe system with the

> receiver vent as the only vent. With exception

> of cast iron in our basement, our radiators are

> convectors from around 1950.

>

> I have been told

> that converting to hot water would result in

> lower gas fuel bills and that it would somehow be

> possible to zone the system without putting

> additional risers. If this is possible from a

> technical point of view, wouldn't the cost of

> conversion be huge compared to fuel savings? In

> considering this question, please also note that

> I have to install a new boiler feeder. If you're

> wondering why, it's because our condensate unit's

> pump just failed and I have just realized

> that:

>

> 1. the condensate unit was only 14 gal.

> versus the minimum 19 specified by

> Weil-McLain

>

> 2. the condensate unit's pump was

> rated at 18 gpm versus 2.1 as specified by

> Weil-McLain.

>

> Items 1 and 2 explain why our

> boiler always seemed to either run low on water

> or over-fill due to use of a Hydrolevel automatic

> fresh water make-up unit.

>

> Your advice

> appreciated.

Steamhead (in transit)

Given the risks, Bill

I wouldn't convert it. Go here for more:

http://www.heatinghelp.com/newsletter.cfm?Id=22

Once the hack-work has been corrected, that system should purr like a kitten. Zone it with TRVs and look into stage-firing the boiler- many LGB units come with 2-stage gas valves as standard.

Given the fact that most of your basement needs no heat at all, you might even be able to reconfigure it for gravity return.