Worcester Bosch 240RSF Hot Water Prob

[ChrisR]

Diaphragm to dhwhe coupling assembly is Worcester part number 87161205070

For Tony this is on the Right as you look at the boiler. (He's obsessed with front bottoms.)

This pic may not work as it needs an account to log on...
Partscenter part 438128

You won't get the part itself from a plumbing merchant, but the O ring is a pretty ordinary sort of size.

 

[Graham81]

Thanks ChrisR that pic helps.

Your right I can easily get hold of the o ring as I've now seen that it is a very small one that sits in a plastic housing, which then sits inside the pipe.

I just want to confirm something. Mine is leaking on this joint shown in your pic where the smaller pipe meets the larger pipe i.e. the small gap in the very middle of the section. Would a new o ring solve this?

 

[Paul Barker]

Yes pull the pipes apart there is an o ring in there.

 

[Graham81]

Right I've stripped it all out again, replaced the o ring and lubed it up, no more leak. I've also lubed the pins and plates of the diverter up, and still no joy??? Still getting warm rads when demanding hot water, and luke warm water.

Couple of things. What is the valve between the central heating flow and return for? And what symptoms would you get if this was open?

Also should the pump run if hot water is demanded?

 

[Paul Barker]

Pump runs to pump water around boiler through main heat exchanger diverter valve and secondary (DHW) heat exchanger.

It has to be the diverter valve.

I don't know if bes would take it back.

I don't have a recent enough photographic memory of the boiler I can picture it mostly but don't know what valve you are referring to between heating flow and return.

A picture would help.

It is however a red herring.

 

[ChrisR]

Was the diverter taken apart at all before fitting? It wouldn't be the first to have the diaphragm in backwards!
Valve tween F and R is I suppose a bypass.

 

[Graham81]

I took the diverter valve apart only to lube it up. I did not take the diaphragm apart, only removed the housing it is in from the end of the diverter to get inside the diverter to lube it.

I can see the diaphragm is working (I think) as it should because it is moving its pin in the correct direction when hot water is demanded so that the micro switches are pressed and the boiler ignites. By the pin in the diaphragm moving in the correct direction, this then creates a gap where the diverter pin can move into (pushed by the spring) so as to close off the central heating loop and open the dhw loop. All seems correct when it is in my hand.
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[scatmanjohn]

Hi..when you stripped out the diverter valve did you just grease the pin or did you clean it back to clean metal with some abrasive cloth first.
If you take out the whole lot and then pull the pin out with some pliers you will be able to see if the diverter section is operating correctly by looking down each port.

 

[Graham81]

It was a brand new valve so didn't have to clean it up. I lubed the pins and the closing off pins.

 

[scatmanjohn]

Why would you want to take a brand new valve to bits to lubricate it?
Are you sure you put it back together correctly.
Try the method i described to see if it is operating correctly.
You will be able to see the different ports opening and closing.

 

[Paul Barker]

I don 't think he initially took it to bits, just after he discovered it wasn't working right. Might have a flaw in the casting or something.

I don't think a boiler of that era would have a bipass, they had to start fitting them because of trv's and dodgy installers not using a room stat, which became a problem later didn't it and still is in some quaters?

 

[scatmanjohn]

Sorry i should have read the earlier post more carefully.
Just a thought...You say that the ch flow pipe is getting hot. Do you mean just close to the boiler or do the rads start to heat up.

 

[Graham81]

After a while the rads get hot. I have also noticed a reduced water temperature, especially if the heating has not been on.

Like stated I only took if apart after it didn't work the first time.

Just a point after one of the last posts, I do not have a room thermostat. The only controls I have are at the boiler, if this makes any difference?

 

[Paul Barker]

If heating has been on then the heating side leaches less of the hot water allowing hot water side to get warmer when the dv is letting a little slip into the heating as in your case.

Lack of rstat though deplorable is not relevant.

You have got a fualty DV. Get another one. BES have a pretty good returns policy.

I would buy the next one from some other source because they may have a whole batch of faulty ones.

If you are prepared to risk cheap suppliers again http://www.ezypart.co.uk/

If not get the Worcester part from Part Centre a leg of Wolsely plc.

 

[Graham81]

I was thinking of biting the bullets and maybe getting one of these boiler insurance packages with BG, N-Power etc. What do you guys think of these?