Do you have a conventional HWS? These are notoriously power-hungry, often poorly maintained and calibrated, and hard to monitor.
You can buy a power meter plug - that sits between appliance and socket - and work your way around almost all your appliances apart from, typically, oven, air conditioner(s), and hot water systems. For those you're going to need to experiment by turning as many things off as you can, to establish a baseline, and review your switch meter periodically for short (several minute) intervals, with and without the larger appliances turned on.
(You can get induction coil systems to report usage of these larger appliances, but they're typically onerously priced.)
If you can isolate the legs of the larger appliances, a CT clamp sensor is sufficient for an idea, and you can get those as handheld meters with screen - or something you plug into a microcontroller board and send the data to a local collection system.
On mechanical blueprints, HWS is the acronym I see used for hydronic heating, and DHW is what I see used for domestic hot water. I’m unsure what the OP meant.
You can buy a power meter plug - that sits between appliance and socket - and work your way around almost all your appliances apart from, typically, oven, air conditioner(s), and hot water systems. For those you're going to need to experiment by turning as many things off as you can, to establish a baseline, and review your switch meter periodically for short (several minute) intervals, with and without the larger appliances turned on.
(You can get induction coil systems to report usage of these larger appliances, but they're typically onerously priced.)