Areas experiencing issues have included Much Wenlock in Shropshire, where the company has been using tankers all week to refill its storage.
Bushbury in Wolverhampton has been affected, where tankers have also been used, and bottled water has been delivered by Severn Trent to vulnerable customers.
Other areas around Wolverhampton including Essington and Featherstone have also reportedly experienced problems. One Featherstone resident complained of no water for 13 hours.
Willenhall has also reportedly been affected, and low water pressure has been reported in Penn and Tettenhall.
Severn Trent has attributed the increased demand in water to the continued use of devices such as pressure washers and sprinklers during the recent hot weather.
Demand for water in the area covered by the company has reportedly been around 300 million litres more this week than last week, with Friday seeing almost the highest ever level of recorded usage.
A spokesperson said: "Yesterday was another day of incredibly high demand for treated water across pretty much the entire area we cover, almost reaching our highest ever level and finishing at 2.275 billion litres of water.
"Our treatment works had a record day of production, working pretty much flat out to keep up with demand as customers use the water as soon as we can produce it.
"We’re seeing low pressure and/or no supply in a number of areas as customers continue to use high-use gadgets like pressure washers and sprinklers, causing demand to be around 300 million litres more than last week."
Problems have continued today , and Severn Trent is at present unable to say exactly how many homes have been affected.
"We don't know the exact number of households currently affected," said a second spokesperson. "But the problem is temporary and it will help if people ease back on their usage, particularly during the evening as this is a peak demand time."
The first spokesperson added: "The problem is not with our raw water supplies, where our reservoirs are around 85 per cent full, it’s customer demand for treated water.
"Our works are pretty much at maximum, and our pipes can only carry so much water, so our storage facilities are gradually draining as we can’t get treated water out quickly enough to meet demand."
Along with sprinklers and pressure washers, the use of hoses and paddling pools has reportedly contributed to the demand.
"A hose/sprinkler uses around 1,000 litres an hour," said the first spokesperson. "A paddling pool holds 400 litres, which is roughly the same as three people’s average daily usage. Jet washers use 36 litres a minute."
Severn Trent has apologised to those who have been affected, acknowledging the importance of good hygiene at this time.
"We’d like to apologise to all customers who’ve been affected by issues in the current period of hot weather as we know just how difficult it must be with the heat and with everyone needing to wash their hands and to have great hygiene during the coronavirus crisis," the first spokesperson added.
Severn Trent has launched a charity challenge, agreeing to donate £1million to local charities if daily water demand falls by an average 150 million litres a day to the end of June.
"It’s a great chance to make sure there’s enough water to go round while also raising money for some great causes," added the first spokesperson.