Hot water / Megaflo won't turn off!

RainbowLaura
RainbowLaura Posts: 240 Forumite
First Anniversary Combo Breaker
Hi everyone,

Yesterday I noticed that our 16 year old Ideal Classic boiler was still firing a while after the timer was supposed to have shut off the hot water and heating. I went up to the airing cupboard and sure enough, the lights on the Honeywell timer panel had gone off. I switched the water and heating to "off" rather than "twice" but nothing, boiler still going downstairs in the kitchen. I ended up having to turn the mains switch off to make it stop.

I have since found that the heating DOES go off when I ask it to, but it seems to be the hot water that carries on going. We have a huge white unvented Megaflo cylinder and you can hear the electrical "humming" from it when it should be off, unless the mains switch is off. It's usually silent unless "on" at the timer.

Within the last six months we have had to have a new PCB in the boiler and some attention due to a dripping tundish from the Megaflo, which was resolved by re-doing the air bubble and then replacing the tundish which had cracked (a pipe had to be moved for this as it was otherwise inaccessible). An added complication is that last week we noticed our Honeywell wired thermostat had broken (the dial had come loose and it was hard to make it "click", although the heating was still working fine). We'd intended to get an electrician out to replace it for us but had not yet got round to it. So this system is costing us an absolute fortune with all the things going wrong with it!!!!

Homeserve won't be coming out until the weekend now, due to their silly 5 hour time slots and me not being able to take a whole half-day off work this week. I just hope it is covered on our basic boiler plan, as I know it excludes cylinders... but does include boiler controls so fingers crossed... Is there anything I can try in the meantime? And should I be worried about safety? I have had visions of an exploding Megaflo and am currently shivering because I'm a bit scared to have it on (and therefore can't have the heating on either). The pressure gauge is in the normal place though which the engineer said was fine when he did the tundish. The Megaflo does have an immersion heater but that's never worked since we've lived here.

Sorry for the essay... any thoughts / advice much appreciated :)

Comments

  • Alex1983
    Alex1983 Posts: 958 Forumite
    It will be the motorised valve stuck open. Turn the boiler stat to zero will stop the boiler firing or switch the heating systems electrical supply off.
  • Thank you Alex1983 :) Hopefully it is that, because according to my policy it would be covered! Should it be safe until the weekend? We need it on for a couple of hours each day to heat the house and the water, but will then put it all off at the mains as you suggested.
  • HomeServe_company_representative
    HomeServe_company_representative Posts: 114 Organisation Representative
    Hi there,

    I understand your concerns regarding your boiler and I’m sorry we’re unable to offer a more specific time slot. If you would like to get in touch using the email address on our profile with your policy details, we can certainly take a look into this. We’d be happy keep an eye on your claim this weekend.

    Kind regards,

    Alice
    Here To Help Team
    Official Company Representative
    I am the official company representative of HomeServe. MSE has given permission for me to post in response to queries about the company, so that I can help solve issues. You can see my name on the companies with permission to post list. I am not allowed to tout for business at all. If you believe I am please report it to forumteam@moneysavingexpert.com This does NOT imply any form of approval of my company or its products by MSE"
  • Hi I have a partly similar issue but unfortunately can't work out how to post my own post as the button is not there.
    I have a gravity fed back boiler so there is no motorised valve. My heating went on initially but then didn't turn off upstairs so I had to turn the gas off to make it stop. When I turned it back on, the heating wouldn't go on but the water won't turn off and you can constantly hear it banging and running in the loft. Even when I turn the gas off, then relit the boilers pilot light, the water started heating up and banging, even though the controls were turned to off. It didn't stop until I turned the gas off in the gas box. Any ideas what could be the issue?
  • Hi I have a partly similar issue but unfortunately can't work out how to post my own post as the button is not there.
    I have a gravity fed back boiler so there is no motorised valve. My heating went on initially but then didn't turn off upstairs so I had to turn the gas off to make it stop. When I turned it back on, the heating wouldn't go on but the water won't turn off and you can constantly hear it banging and running in the loft. Even when I turn the gas off, then relit the boilers pilot light, the water started heating up and banging, even though the controls were turned to off. It didn't stop until I turned the gas off in the gas box. Any ideas what could be the issue?
  • can constantly hear it banging and running in the loft
    Have you checked the header tank (in the loft) is functioning correctly, and the float isn't stuck or something?
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