If you appear to have no hot water and heating then one thing to always check before contacting a gas engineer is that the boiler has pressure in it.
To do this you need to check the pressure gauge on the boiler. Generally if the pressure is below 1 bar then it will need to be topped up.
Please refer to your boiler manual. If you are having trouble and need advice before calling out an engineer and getting charged unnecessary call out fees then please contact us on 01909 470402 where we will be more than happy to talk this through with you.