Adequate Water Heater Capacity?

PDQ issues applicable across all PDQ Yachts (or if you can't find a place for something, it probably belongs here for now)
Post Reply
User avatar
mikemak777
1st mate
1st mate
Posts: 49
Joined: Thu Jan 15, 2009 12:10 pm
Location: Dana Point, California/1996 32 Classic "THIRD WISH"

Adequate Water Heater Capacity?

Post by mikemak777 »

Question for the oracles of experience ....

I am fitting am refitting my boat with an instant hot water heater and have no idea which capacity is adequate. My highest concern is having adequate hot water when using the shower.

I would prefer to go with the 1.6 gpm unit as it is smaller and does not require a flu. Because my boat has the deck vent outside the starboard forward deck, it leads me to believe that it was originally fitted with a 3.2 gpm unit (which requires a flu), unless technology has improved over the last 14 years.

Thanks for your help,

Mike.
ATTITUDE
skipper
skipper
Posts: 60
Joined: Thu Feb 10, 2005 9:44 pm
Location: Sewall's Point, FL

Re: Adequate Water Heater Capacity?

Post by ATTITUDE »

Mike:

Having lived with a wife and three daughters and being last on the list for a shower I found that there was no such thing as having enough hot water. However, now with just a wife onboard, the Excel ventless model supplies plenty of hot water. The manufacturer states: "It delivers over 96 gallons of hot water an hour with a 45 degree rise in temperature. This means that if your tap water is at 65 °F , it will instantly deliver 96 gallons of hot water an hour of water at 110 °F."

I mounted my unit in the lazarette just aft of the head. Easy to get scolded if not careful.

Hope this helps.

Doug
ATTITUDE
Captain Doug
Admiral Jeannie
Sea Dog 1st Class Paca

ATTITUDE - the last of human freedoms (Viktor Frankl)
User avatar
mikemak777
1st mate
1st mate
Posts: 49
Joined: Thu Jan 15, 2009 12:10 pm
Location: Dana Point, California/1996 32 Classic "THIRD WISH"

Re: Adequate Water Heater Capacity?

Post by mikemak777 »

Thanks for the info, Doug. Without knowing the flow rate of my shower, it was hard to determine if the 1.6 gpm flow rate would be adequate. It strikes me now that I can measure the flow rate per minute with a bucket of known capacity. Nonetheless, I'm still wondering what capacity the 32s originally came with.
User avatar
mikeandrebecca
admiral
admiral
Posts: 346
Joined: Sun Jan 25, 2009 1:38 pm
Location: In transit, s/v Zero To Cruising, PDQ 32045
Contact:

Re: Adequate Water Heater Capacity?

Post by mikeandrebecca »

I just looked through the manual that I have to see if I could find that info for you. Unfortunately I couldn't. We have a Bosch model W125-ODS unvented if that helps.
User avatar
mikemak777
1st mate
1st mate
Posts: 49
Joined: Thu Jan 15, 2009 12:10 pm
Location: Dana Point, California/1996 32 Classic "THIRD WISH"

Re: Adequate Water Heater Capacity?

Post by mikemak777 »

Thanks, Mike. It doesn't appear that Bosch neither makes this model anymore, nor anything similar. All I could find were vented models.
Does yours have a pilot burning at all times?

Mike.
User avatar
mikeandrebecca
admiral
admiral
Posts: 346
Joined: Sun Jan 25, 2009 1:38 pm
Location: In transit, s/v Zero To Cruising, PDQ 32045
Contact:

Re: Adequate Water Heater Capacity?

Post by mikeandrebecca »

It would have if we left the solenoid on, which we don't do. We did do that all last season but are being much more cautious these days. It isn't a big hassle to light it as it's in the galley where we would normally use water. The only issue is that unless we light it, we wash our hands with cold water in the head, which again, for us is not a big deal.
User avatar
thinwater
admiral
admiral
Posts: 1110
Joined: Mon Sep 22, 2008 8:08 am
Contact:

Re: Adequate Water Heater Capacity?

Post by thinwater »

mikemak777 wrote:Question for the oracles of experience ....

I am fitting am refitting my boat with an instant hot water heater and have no idea which capacity is adequate. My highest concern is having adequate hot water when using the shower.

I would prefer to go with the 1.6 gpm unit as it is smaller and does not require a flu. Because my boat has the deck vent outside the starboard forward deck, it leads me to believe that it was originally fitted with a 3.2 gpm unit (which requires a flu), unless technology has improved over the last 14 years.

Thanks for your help,

Mike.
I would be VERY concerned about not having a flu, even on the smaller size. We're talking about some very confined spaces and your going to run low on oxygen. There is no "new technology" that is going to help that. I don't worry about PFDs, but I do worry about falling asleep and not waking up.

BTW, it doesn't need to be a bucket - a graduated mixing bowl would be easier. Count the seconds per quart.

BTW, if you use an instant heater, the hot water generally needs to be wide open, or it will cycle on/off, which you won't enjoy. You temper with the cold water.
Writing full time since 2014.
"Rigging Modern Anchors,"Seaworthy Press, https://www.amazon.com/Rigging-Modern-A ... 1948494078
Book Store. http://sail-delmarva.blogspot.com/2017/ ... store.html
User avatar
mikemak777
1st mate
1st mate
Posts: 49
Joined: Thu Jan 15, 2009 12:10 pm
Location: Dana Point, California/1996 32 Classic "THIRD WISH"

Re: Adequate Water Heater Capacity?

Post by mikemak777 »

Thanks for your input, Drew. I didn't know the hot water had to be turned on full. If that is the case, I'm fairly confident that 1.6 gpm would be adequate although I think the factory fitted the boats originally with a higher output unit. I suppose I would have to turn down the water temp to avoid using more than 1.6 gpm. I would think mixing cold water with the 1.6 gpm flow would be much too much water useage.

Good point about oxygen depletion - my fridge is propane (with a constant pilot) and aside from potential leaking that would be an issue. Although the boat is not airtight (by design?), I'm not sure how comfortable I would be sleeping at night with all the ports and hatches closed.

On the Classics, the hot water heater is installed in the starboard forward compartment so oxygen depletion of the living quarters would not be an issue. But lighting the unit each time to use it would be a hassle. The Excel and similar type water heaters out now have an electronic ignition which is nice - as long as it works. Everyone posting about them seems to have had a good experience, and you can't beat the price at approximately $200.

Thanks again to everyone for all their help.

Mike
amytom
admiral
admiral
Posts: 694
Joined: Fri Oct 05, 2007 10:57 am
Location: Orlando, FL S/V DogHouse PDQ32009

Re: Adequate Water Heater Capacity?

Post by amytom »

Get the Excell. You won't be disappointed.
Post Reply