The household that doesn't pay its water bill cannot by law be cut off or restricted from the water supply. However, there have been reports that some companies have disconnected households anyway, claiming the premises were not occupied.
In some circumstances the gas or electricity supplier may disconnect the domestic consumer that is not paying its bills. However, "Suppliers must take all reasonable steps to avoid disconnecting an energy supply for debt. It should always be a last resort and avoided wherever possible" (Ofgem, the regulator).
The question asks for "possible" repercussions, not probable or usual.
So here are some "possible" repercussions.
The utility company may pursue the debt; first by mail, then via a debt collection agency and may ultimately seek court orders to resolve the matter one way or another.
Generally, utility companies and the regulator Ofgem don't want things to get to court and will try to agree a repayment plan with the debtor and/or (in the case of electricity or gas) offer to install a prepayment meter. There are payment support options for households in financial difficulties but the question seems to be about outright refusals to pay.
All creditors pursuing a debt are expected to follow the Pre-Action Protocol for Debt Claims. This should be followed before a court order for a County Court Judgment for the debt can be made. Failure to follow the protocol does not invalidate the debt but can affect the court's decision.
If the creditor wins a county court judgment (CCJ) against the debtor, the debtor will be obliged to pay the debt at a rate the court decides is appropriate.
A CCJ is recorded on the Register of Judgments, Orders and Fines. The Register is checked by companies to determine the credit-worthiness of applicants for credit cards, loans, mortgages, some bank accounts and rental agreements. If the debtor pays the full amount within one month of the CCJ, the record can be removed from the Register. If the debtor pays later, they can get the record marked as 'satisfied' - it will stay on the register for six years but searchers will see that the debtor paid the debt. If the debtor sticks to the payment plan the record can reflect this. Otherwise the record of the debt remains on the Register for six years.
If the debtor still refuses to pay, the debtor may expect visits from bailiffs who will ask for payment and, failing that, the bailiffs might try to remove property to sell at auction to raise money to cover the debt and the bailiffs' costs.
The creditor may seek an order for an attachment of earnings or an attachment of benefits / benefit deductions. In this case, the employer or benefits agency is ordered to divert money from the wages or benefits to the court that made the order, and the court sends the money to the creditor - the debtor doesn't receive that money. (The benefits attachment is likely more appropriate for non-payment of council tax.)
The creditor may seek a third-party debt order, which orders the debtor's bank to freeze money in the debtor's account to the amount of the debt.
The creditor may seek a charging order, which secures the debt against the debtor's property (e.g. their home if they own it). This can be followed up with an order for sale, which obliges the debtor to sell that property and the debt will be paid from the proceeds.
The creditor could seek a court order that allows them to change the utility meter on the property to a prepayment meter. In this case the debtor has not been disconnected as such but they must pay (or get help to pay) in advance for their electricity or gas consumption.
As noted earlier, the last resort is disconnection of the gas or electricity supply.
In terms of criminal law, I don't know if any such debtors have been charged with illegal abstraction of electricity or gas but those seem like "possible" charges.