Worcester Bosch Highflow 400 Troubleshooting

Are you concerned about your faulty Worcester Bosch Greenstar boiler?

Worcester Bosch Highflow400 hot water issues. The highflow 400 is/was a great boiler when it's working, giving plentiful hot water. But when they start playing up, they can be a real pain to repair. The biggest problems they suffer with is restrictions in the plate heat exchanger (the part that heats the water that comes out of the tap).

If you own a Worcester Bosch Greenstar, the chances are your boiler is probably under 10 years old, as most of these models were first introduced around 2004/2005.

As a heating engineer, I know it can be particularly stressful for my customers when their boiler is playing up – especially when you don’t know what’s wrong and how big a job it’ll be to fix.

To help you out, I’ve listed four of the most common problems myself and other engineers have found over the many years of working on faulty Worcester Bosch Greenstar boilers, below:

NOTE: This blog does NOT cover older Worcester models. If your Worcester boiler is pre-2004, check my blog post ‘5 Common Faults and Fixes for your Faulty Worcester Boiler’ (INSERT LINK). Free download pahari songs of karnail rana.

Common fault 1: Low boiler pressure

The Cause: If you’re done all the usual checks (including checked the radiators for leaks and looked at the pressure relief valve without finding any faults), it could be the automatic air vent. You’ll be able to tell by taking off the plastic bottom panel and seeing if there is rusty water.

The Fix: This is usually just a case of dropping the pressure, pulling out the retaining quick release pin, and replacing the air vent. Then all we’d need to do is refill the system and test.

Common fault 2: EA error code

The Cause: This is by far the most common problem we’re called out to, and it’s caused by the condensate pipe becoming frozen or blocked. This is usually down to installer error rather than a fault with the boiler.

You can confirm it’s a problem with the condensate pipe by pressing the reset button and when the boiler fires up, it should make gurgling noises before cutting out again.

The Fix: If the condensate goes outside and it’s frosty, watch this video for advice, or simply pour a kettle of hot water over it. It may be the condensate trap is blocked and the boiler needs to be serviced.

Common fault 3: Boiler failing to ignite

The Cause: If your boiler refuses to ignite, and you can hear it going through the sequence before making a ticking noise (trying to ignite), it could be that the gas has been turned off or a fault in the ignition leads.

The Fix: Check there is gas coming into the house, as it may have been turned off outside. If you have a prepaid meter, check it is topped up. Alternatively, your ignition leads may need replaced or the boiler serviced.

Common fault 4: Strange banging noises

The Cause: If you hear a strange banging noise when your boiler fires up, this is usually a problem with the gas valve communicating with the fan speed.

The Fix: Call a Worcester Bosch service engineer or an accredited engineer, who will be able to take a look at it for you.

Call an experienced Worcester Bosch engineer

Worcester Bosch Greenstar boilers are very reliable, well-built boilers. However, if you do experience problems, I’d recommend either calling in a Worcester Bosch service engineer or Worcester Bosch accredited engineer.

It’s definitely better to call someone with specific product knowledge, rather than just going straight to your local gas engineer.

Conclusion

Sometimes there’s nothing worse than having to deal with boiler faults and error codes. If you have a faulty Worcester Bosch Greenstar boiler, follow my tips above for solving some of the most common faults these boilers experience. Including:

• Low boiler pressure

• EA error code

• Boiler failing to ignite

• Strange banging noises

Remember, if you’re in any doubt, call an experienced Worcester Bosch service engineer or accredited installer.

Good luck!

Hi All, I wondered if anyone could throw some light on a long running issue I'm having. I have a roughly 12 year old Highflow400 - yes I know it's getting on a bit!
I have been experiencing intermittent hot water issues. This began happening at first quite randomly, heating would and always has worked fine but now and again there would be absolutely no hot water. A couple of times the overheat function had tripped requiring me to reset by pushing the two reset buttons simultaneously. Most of the time however the overheat function had not cut in, the buttons had not deployed. The only way I've ever been able to restore hot water when the buttons hadn't deployed is by turning the boiler on and off at the mains - sometimes several times.
The symptoms started to become more consistent a few months later, hot water was generally lost during high demand for example if I had a shower it would be fine but if my wife showered soon after it would be completely cold.
We have homecare and they have been out several times, the last time I thought they'd nailed it as they replaced a part 'which stops the temperature getting so high as to overheat the boiler' they said the part was physically broken but I'm afraid I never asked what it was although I think it was a switch of some kind. Anyway, boiler went great for a month and now the problem is back. It's slightly different now though in that high demand (2 consecutive showers) doesn't seem to have any real bearing. It seems completely random again. I got up at 5am this morning and hot water was gone, it took me ten mins of switching on and off at the wall switch and then it came back. Gas engineers were back out today and could not replicate the problem!!
Does anyone have any ideas at all? For info the pressure is fine. I'm tempted to bite the bullet and replace but it bothers me that this must be something relatively straightforward and fixable.
Thanks in advance for any feedback
Ross