Worcester boiler hot water issue

[poppymango]

Brand new boiler, Worcester Greenstar 8000. Heating working fine, but we can’t get the hot water going.

All instructions we can find tell us to press the tap button on the left to adjust the water temperature, but when we do that the temp doesn’t come up, just a series of dashes on the display (see pic).

I’ve tried resetting it, but no joy.

Really hoping someone on MN is a plumber or has had this issue before - help please!!!

Check the boiler pressure (shouldn’t be below 1.0)?

I had a problem with my boiler recently. When the engineer came he said my drain was blocked and it was stopping the boiler working!! 😳 Embarrassing!

It won’t show me the boiler pressure either 🫤 it just shows me a series dashes again. But I lets me adjust the radiator temperature no problem, and they’re working fine.

Have you looked on YouTube? I've fixed my boiler from videos on there a few times.

From Chat GPT:

If your Greenstar 8000 is showing four dashes (----) on the display, that usually means the boiler is in standby mode or the display is not receiving input from the controller. It’s not an error code, but it suggests the boiler isn’t being told to produce hot water.

Here’s what you can try:

1. Run a hot water tap

• Turn on a hot tap fully and let it run for a minute. • Watch the boiler display. Do the four dashes change? Does the boiler start making noise (igniting)? • If nothing happens, it’s likely the boiler isn’t detecting hot water demand – possibly due to a diverter valve issue or flow sensor fault.

1. Check pressure

• Look underneath or on the front for a pressure gauge. • Is it reading between 1.0 and 1.5 bar? If it’s below 1.0, the boiler might not work properly.

1. Reset the boiler

• There should be a reset button (sometimes part of the control dial). • Hold it for 5 seconds. The boiler should click or restart. Then try running the hot tap again. • Do the four dashes disappear or change?

1. Thermostat or controller issue?

• If you have a wall thermostat or smart system (Hive, Nest, etc.), check: • Is it asking for hot water? • Is it connected properly to the boiler? • Try boosting the hot water or turning the schedule on manually.

Likely causes based on symptoms:
• Diverter valve stuck – common when heating works but hot water doesn’t.
• Flow sensor or microswitch fault – boiler doesn’t realize you’re calling for hot water.
• Control system issue – the boiler isn’t receiving the ‘hot water’ demand signal.

The MN you need is @pigletjohn

It’s a new boiler. Get the fitters back to get it working. Should also have manufactures warranty. Read that and see if it offers phone support

Do you have a rest button next to the boiler. Ours has a little red light and a green reset button. The plumber said the red light should be on but if not to press the green button to reset.

Get the installer back to look at it

Contact the installer. They should have tested it, leaving it operational and ideally given you a quick run through of how it operates