Brianosaur
New Member
Remolded my bathroom last year. Turns out, as feared, the new shower head and shower valve uses too many GPM to keep up with my tankless oil fired boiler. Two or three minutes into a shower I lose the hot, or pretty much the "nice and hot".
Pre-remodel I would just keep the pressure low and adjust hot & cold knobs separately to get away with a decent shower. We knew not to run the dishwasher or do laundry while showering. The new single lever thermostatic mixer doesn't let me dial in hot/cold pressure that well and the large rain 2.5 gpm head doesn't help the situation. If I switch to the hand held sprayer it will allow the boiler coil to catch up enough and I can get hot water all day long.
(1.) I am uncertain what size TWH I would need to make up the additional temperature from a luke warm (leaning cold) shower.
The size charts state geographic area based on ground water temps but since the water will be mostly/mildly pre-heated in my boiler would I need as large of a unit?
Or should I run the cold line to the TWH and the hot output in parallel to the existing hot line to the shower, and get a standard size unit for my location & gpm need?
Thanks
Pre-remodel I would just keep the pressure low and adjust hot & cold knobs separately to get away with a decent shower. We knew not to run the dishwasher or do laundry while showering. The new single lever thermostatic mixer doesn't let me dial in hot/cold pressure that well and the large rain 2.5 gpm head doesn't help the situation. If I switch to the hand held sprayer it will allow the boiler coil to catch up enough and I can get hot water all day long.
(1.) I am uncertain what size TWH I would need to make up the additional temperature from a luke warm (leaning cold) shower.
The size charts state geographic area based on ground water temps but since the water will be mostly/mildly pre-heated in my boiler would I need as large of a unit?
Or should I run the cold line to the TWH and the hot output in parallel to the existing hot line to the shower, and get a standard size unit for my location & gpm need?
Thanks
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