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  • FIRST POST
    • kalialba
    • By kalialba 19th Jun 17, 10:54 PM
    • 25Posts
    • 1Thanks
    kalialba
    Boiler Problem -Advice
    • #1
    • 19th Jun 17, 10:54 PM
    Boiler Problem -Advice 19th Jun 17 at 10:54 PM
    Problem started with my shower where the water would suddenly go cold then after a few minutes runs hot again. The shower was replaced but it is still happening.

    Just had a plumber to look at the boiler, it is now 13 years old and is worcester bosch 35cdi ii. The plumber has said it is likely to be the diverter valve.

    He said in this particular boiler it is very difficult to get to and whilst he could repair it, it is not guaranteed to work, even if it does it could fail fairly soon or develop other problems with washers leaking etc. (I really don’t know what I am talking about here so just repeating what he said)

    Repair would be £250-300.

    He advised that due to age it may be better to replace with a new boiler which would be much more efficient. Apparently I don’t need 35k boiler so a 30k would be big enough.

    Has quoted around £2000 for a new worcester bosch combi, £1500 for a Baxi or £1850 for intec eco combi boiler with 10 year guarantee.

    Really just wanted some advice whether it really is not viable to repair current boiler on the basis it could just be continuing problems and good money after bad.

    Should I just replace the boiler given the age and that a new boiler would be more efficient.

    Would you stick with Wocester if I go for a new boiler.

    Any advice appreciated.
Page 1
    • Chanes
    • By Chanes 19th Jun 17, 11:17 PM
    • 841 Posts
    • 522 Thanks
    Chanes
    • #2
    • 19th Jun 17, 11:17 PM
    • #2
    • 19th Jun 17, 11:17 PM
    We had a Vaillant fitted in 2015 for £1500 to replace an old boiler. I don't know about boilers but 13 years seems old but if the repair lasted a few years it might be worth the fix. I am sure there are some Gas fitters who post on her who will give better advice. I'd fit a new boiler, money permitting, obviously.
    • Alex1983
    • By Alex1983 20th Jun 17, 12:12 AM
    • 312 Posts
    • 165 Thanks
    Alex1983
    • #3
    • 20th Jun 17, 12:12 AM
    • #3
    • 20th Jun 17, 12:12 AM
    It's not a very nice job to replace the diverter valve, which is probably why he's pushing towards a new boiler. It's not a bad boiler, just not to nice to work on. I'd repair it personally and get the plate heat exchanger cleaned at the same time, that needs to be taken out to get to the diverter valve.
    • kalialba
    • By kalialba 20th Jun 17, 10:25 AM
    • 25 Posts
    • 1 Thanks
    kalialba
    • #4
    • 20th Jun 17, 10:25 AM
    • #4
    • 20th Jun 17, 10:25 AM
    Alex 1983, thanks for your reply. Can I ask you further advice please. The plumber did not actually do any inspection or test on the boiler and just said it would be the diverter valve. I appreciate that someone in the trade has or should have a range of experience and will base advice and judgement on that experience.

    My water pressure has never been good but recently seems to have deteriorated further. The bathroom and shower are upstairs and boiler is downstairs. The problem seems to only be with the shower and very occasionally bathroom sink. I did mention this and the plumber said that would be that the taps closest to boiler would have less problem and upstairs is more liable to run cold as further away from boiler.

    I have been looking at some of your other threads as I see you have given loads of advice so I assume this is your line of work. I have seen posts where you mention mains water pressure flow.

    I then tried to time the cold water tap to run 2 litres of water and it took 40 seconds!! I did look on United Utilities re water pressure and they say you should be able to run 4.5 litres in 30seconds so this is obviously a further problem I need to address.

    Could this be the issue with the water running cold in the shower and the boiler is just not getting enough water.

    Thanks in advance for any advice
    • Alex1983
    • By Alex1983 20th Jun 17, 11:40 AM
    • 312 Posts
    • 165 Thanks
    Alex1983
    • #5
    • 20th Jun 17, 11:40 AM
    • #5
    • 20th Jun 17, 11:40 AM
    The diverter valve in your boiler will fail one of two ways.

    1. When you run hot water your radiators will heat as well as your hot water, this is passing.

    2. The diaphragm in the end wears it has a small tear which stops the boiler for firing for hot water.

    You boiler has a led for the burner being on and another one for the hot tap being on. Run a hot tap for 5 mins or so and make sure the two leds stay lit, after the five mins make sure none of the radiators are hot. If they both stay lit and doesn't heat the radiators this will prove the valve is not passing and the heat exchanger is probably ok.
    Next you can run the shower and see what the leds do then, I would guess the demand led will go out.

    I would suspect the diaphragm has worn and the low flow rate of the shower is not enough to operate the boiler. A temporary option is to turn the basin hot tap on slow when your having a shower.

    There is a service kit available for the diverter valve which would cost around £25 max and involve removing the valve and stripping it down and replacing the inners. The problem you will have I would say is getting someone to do that as it's not a very nice job to do and many will want to replace the complete valve.
    • kalialba
    • By kalialba 20th Jun 17, 4:46 PM
    • 25 Posts
    • 1 Thanks
    kalialba
    • #6
    • 20th Jun 17, 4:46 PM
    • #6
    • 20th Jun 17, 4:46 PM
    Thanks a lot, I really appreciate your advice.
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