We’ve got a Worcester boiler. A couple of months ago, the water when running a bath would warm up fine but then go cold after a short time. Using my expert plumbing and heating knowledge (i.e. I guessed and googled), I put it down to a faulty flow restrictor valve and only turning the tap 1/2 open has cured that. However, this morning I put the shower on (which has never had a problem) and it did the same thing, but turning it 1/2 on hasn’t cured it. Now, the boiler kicks in and we get about 15 seconds of hot water, it then cuts out and tries to kick in again 5 seconds later but there’s now a loud, nasty sounding crunching noise from it when it kicks in. We can still get hot out of all the taps fine. Haven’t checked the heating, wont be turning that on for a while anyway I’m wondering if the flow restrictor has disintegrated completely and this is the crunching noise? Is that likely, or is it possible that it’s a bigger issue and we’re in for a hefty bill?
You may need to give more info. Is it a combi? Is the shower directly fed or a thermostatic control? Test the heating now before it is a proper issue, like no heating when very cold. Also, if recently installed the installers hand the system over to Worcester Bosch for warranty and maintenance. Also worth giving their tech line a call as they are usually quite helpful.
Cheers bud, it is a combi. We’ve been here for 4 years and it wasn’t new when we moved in, at a guess it is probably about 7 or 8 years old, but that’s only based on knowing when the previous owners did the extension that it’s now in. I believe it’s a direct feed into a normal mixer valve, but I may be wrong there. The bath certainly is direct and no reason to think the shower is any different. I have a friend of a friend who is going to pop over, but can’t until next Tuesday
In my experience cycling hot and cold with a high output (shower / bath) was down to blocked plated heat exchangers. I've had this (very bad) on a Vaillant, and also (not so bad) on our current Worcester Bosch Greenstar. Removing the plated heat exchanger and flushing it through improved matters no end. It was just a massive job to get the HE out as space is very tight.
We've had that too but not with crunching noise. Have been through 3 plate to plate heat exchangers in 11 years on a Glow worm combi plus filling loop valveand PRV. Regularly flush and fill inhibitor to heating system now.
One thing I was surprised about when I called the boiler manufacturer was that they could set up a repair plan for a year with the boiler getting fixed included for a reasonable cost. We got that and a nice warm house within a week!
There is no pressure in there at all! Just topped it up to 1 bar, turned the kitchen tap on and the pressure just dropped down to 0. Turn the tap off and it goes back to nearly what it was.
We have this, every few years I have to replace the heat exchanger but we do live in a hard water area.
You have more than one issue going on. your initial problem is most likely the plate heat exchanger is either blocked on the hot water side due to limescale. Or blocked on the primary boiler side due to contamination in the boiler/ heating circuit. the banging noise is from the water literally boiling in the primary heat exchanger due to a lack of circulation. This could be related to the plate being blocked. It could be that the wTer pump has failed or it could be that the water pump isn’t spinning vos it’s full of air. your pressure is shooting up as water is trapped in the boiler. Becoming super heated. Expanding rapidly and increasing the pressure in the boiler. you need a decent heating engineer.
The correct way to change the plate on most Worcester’s is to remove the hydrolic block and change the plate on the bench. It’s possible to just drain the boiler and remove a couple of the pipes, creating just enough room to manoeuvre the plate out. my money is on your issue being the water pump.
It goes without saying that the other major problem you have is that someone unfortunately fitted a Worcester in your house. Schoolboy error of judgement. one positive is that unlike most other boilers, because they are essentially made of pig iron, they do at least hold their scrap value.
Haha - are WB that bad? I'm finding I get less H/E blockages than the Vaillant (live in a similar area) and it seems to handle more demand better (could just be a bigger boiler though - cant remember what our old one was)
