Paying upront for oil boiler service plan?

Beckyy

We have oil heating and our Worcester boiler is due a service. I was looking to take out a service plan with Worcester which appears much better than just paying one off to have a service with them.

The first option is a one off service charge of £118, inclusive of VAT.

As your product is no longer covered by our manufacturers guarantee, or by a maintenance contract, we will need to reserve our breakdown fee of £230 at the time of booking, to cover the cost of any parts that may be required for your product. If parts are required, our engineer will inform you of this during the visit and should we find that significant or structural parts are required, or that the product is beyond economical repair then our engineer will quote you a revised charge on the day.

The second option is a twelve month service plan which is administered for Worcester by Domestic and General. The cost of the plan is £171, payable by direct debit in twelve monthly instalments of £14.25.

I really hate having DDs coming out of my account every month for things like this. Bit of a strange question, but if they were to let me, would there be any obvious reason not to pay the £171 outright?

Or would people recommend going to a local company instead?