Relax in the knowledge that our boilers won’t let you down

Our boilers are built to last, and fitted correctly, will give you years of trouble-free service. We pride ourselves on the fact that our boilers are extremely robust and reliable. For your peace of mind, all of our boilers come with either 2, 5 or 10 year warranties*. When you buy a Sime product you can relax in the knowledge that it won’t let you down, and in the unlikely event that you encounter a problem, our network of approved Sime engineers will respond quickly.

Our promise to you

We promise to attend all in-warranty breakdown calls within two working days from the initial call to our service department for domestic boiler products.

Clear error codes for easy troubleshooting

If there is a problem, the boiler will display a fault code indicating what is wrong. By reporting this code to your installer or the Sime service department, the problem can be diagnosed, and in most cases, fixed over the telephone. If an engineer does need to come out to you, reporting the fault code will ensure that the service agent comes prepared with the correct parts so that the problem can be resolved on the first visit.

Our highly-trained customer support team and technical services team are available Monday to Thursday from 8.30 am to 5.00 pm and 8.30 am to 3.45 pm on Friday, please call 0345 901 1114 for assistance. Out of these hours, you can contact us by email on

Annual service please!

We invest in the technology and controls inside your boiler and put our name on every one of them to bring you the reassurance that comes from choosing a Sime boiler. We are confident that your Sime product will give you years of trouble-free operation if maintained correctly and serviced annually. Please make sure that you arrange for your Sime boiler to be serviced on or before the anniversary of installation by a qualified Gas Safe registered heating engineer.  This will help your boiler to remain in excellent, operational condition and ensure that you stay within the terms of your warranty agreement.

Unexpected issue?

In the unfortunate event that you have an issue with your Sime boiler, and your user manual does not help you resolve it, we have a nationwide network of qualified, Gas Safe field engineers and appointed service agents on hand to help you. We are committed to delivering the highest levels of customer service and support. Our customer service and technical helplines are manned by highly-trained professionals who will endeavour to diagnose and resolve faults over the telephone, and arrange for an engineer visit if necessary. We will attend all in-warranty breakdown calls the next working day, where possible.

* Terms and Conditions