Electricity bills are going up by 17pc, and gas bills by 23pc from October 26.
It is the sixth price rise from Flogas Energy since the start of last year, as there were four increases last year.
There is no rise in the standing charge this time. Flogas has some of the highest standing charges at up to €600 a year for electricity.
The supplier has over 25,000 customers.
The latest price rise will add around €340 a year to electricity bills and around €395 to gas bills, Daragh Cassidy of price comparison site Bonkers.ie said.
“When all increases since the start of last year are added up it's adding over €1,700 a year to people's electricity bills and over €1,700 to their gas bills.
Help in next week's Budget can’t come soon enough.”
In the last few weeks there have been- price increases of between 20pc and 40pc from SSE Airtricity, Electric Ireland, PrePayPower, Energia, Community Power and Bord Gáis Energy during the current wave of price hikes.
Since the start of 2021 there have around to 60 separate price-increase announcements.
These have meant the annual cost of supplying a typical home with electricity has more than doubled to €2,000.
There has been a similar rise in gas costs, with home-heating oil prices also doubling to around €1,280 for 1,000 litres of the fuel.
And it was revealed by this publication this week that standing charges have gone up by as much as €300, with some energy suppliers charging households €700 in standing charges for electricity alone.
Taoiseach Micheal Martin said there was no room for energy companies to exploit the current energy crisis by hiking up standing charges for customers.
Flogas Energy said the latest rise was due to the continuing and unprecedented increases in wholesale gas prices and the associated increases in wholesale electricity costs.
Flogas general manager Sean O’Loughlin said: “Energy cost increases are affecting all suppliers and while we are continually looking at ways to minimise costs for our customers, we have no option but to increase our rates in the current environment.”
The supplier of gas and electricity said it will customers affected by the new price rise through its customer service team.
It said it has a range of options, including payment plans, budget pay and pre-payment meters.
“We would ask any Flogas customer who is facing financial pressure around their energy bills to contact us,” Mr O’Loughlin said.
Flogas said it was increasing the payment to homeowners and small businesses using solar panels under its SolarGen Microgeneration scheme to 24c per kWh.
This is the highest rate available to microgen customers in the market, it said.
Flogas encouraged all customers to ensure they are on a discounted contract, and where they have a smart meter installed, to switch to a Flogas Smart Tariff.