Sludge bucket problems

Discussion in 'Plumbers' Talk' started by OldHouseNewOwner, Aug 1, 2020.

  1. OldHouseNewOwner

    OldHouseNewOwner New Member

    Hi All,

    moved house a couple of years ago. had a few issues with central heating - to be honest it’s an old system, CH mix of 15mm & microbore, Some radiators don’t heat up, others museum pieces and not in a good way. I plan to get the whole lot ripped out and replaced.

    A few weeks ago, hot water packed up. Wife phoned up boiler manufacturer- they asked a few questions, resulting in suggestion was external pump broke. Looked like no heat travelling from boiler to tank.

    No issue I thought - got a new grundfos, and got a man in to change.

    system drained, pump changed, refilled, still doesn’t work.

    I should add at this point that a lot of space around the tank was boxed in to form a bathroom cupboard. Access to the tank did not appear to be a design consideration for this in any way. There were two pumps present which should have given some indication something was odd but...

    So... After the plumber left, I removed all the boxing in, and, much to my wife’s utter delight, some of the flooring from next to the boiler.

    I’m not in the industry but reading up online it looks like what we have is not a normal tank but a “thermal store” from around 1990.

    The obvious answer to my problems is to rip it all out and start again.

    BUT - ideally I’d like to delay that until I’ve had some building work done to convert the garage - with a view to whacking a floor standing combi in there when the space has been converted.

    We are currently living with no hot water, there is no immersion heater in the store, and I’m having issues trying to find someone experienced in these old heaps who could have a look and possibly get it running for a few more months to buy me time to move forward on the garage conversion..

    It struck me that whacking an immersion heater in might buy me some time, but I’m worried that if that was a good idea, I can’t fathom why it wouldn’t have been done already...

    Any thoughts?
  2. andy48

    andy48 Active Member

    1. Very difficult to offer advice without pictures. Airing cupboard / thermal store (if it is) and pumps would be a good start.
    2. What makes you think it is a thermal store. There are heating / hot water systems with 2 pumps rather than with motorised valves.
    3. Does the central heating still work, albeit only partially?
    OldHouseNewOwner likes this.
  3. OldHouseNewOwner

    OldHouseNewOwner New Member

    Thanks for your response Andy!

    should emphasise - no criticism of plumber intended - very courteous chap, came round, did job I asked of him, and satisfied himself old pump was broken before swapping it out.

    Pictures attached - single header / expansion tank - nothing in loft.

    2. Good question - Suspicion mostly. Pipe work seemed similar to page 12 here -–-F6022884-v2.pdf did have a couple of other lads out to take a look when I opened up the cupboard- can’t remember their exact words but they suggested it looked like an older style of system. Presence of what looks like a temperature valve and a number of different pipes going in and out the tank led me to suspect it’s a thermal store - could obviously be very wrong here. Definitely no sign of any motorised valves though.

    3. Central Heating does not work at all, but used to partially. Heat does not seem to be transferred from the boiler to the tank - pipes are cold at tank end when hot at boiler end.

    Attached Files:

  4. andy48

    andy48 Active Member

    1. Tend to agree with you - does look like a thermal store system, although most I've seen have an integral header tank.
    2. Looks as if it has a blanking plate for an immersion heater near base. Probably not fitted if no Economy 7 tariff present and gas is about 1/3rd the cost of normal rate electricity for water heating.
    3. I'd start by trying to trace heat path from boiler. Is it circulating from flow to return? If not, suspect other pump or a blockage somewhere.
    4. Very difficult to suggest anything really positive without being in front of it.
    5. As a short term emergency measure you could consider fitting an immersion heater. But:
    5a. I'd try just slackening the blanking plug with the cylinder still full. Less likely to damage cylinder. If it won't budge, no immersion.
    5b. You'd have to drain the entire system. The water should contain a lot of inhibitor (roughly 1 litre per 100 litres of system water - so probably 3 to 5 litres). This would need to be replaced on refilling.
    5c. You'll need a source of electricity. This should be a dedicated cable back to the consumer unit. It shouldn't be a plug into a a ring socket. Need a double pole switched cable connector.
    5d. Fit a good quality immersion heater. Titanium if you are in a hard water area.
    5e. Make sure immersion is connected with proper heat resistant cable and all connections are really tight.
    5f. Refill, make sure no leaks, drain 20 litres out, add inhibitor via F&E, make up to volume.
    The Teach and OldHouseNewOwner like this.
  5. OldHouseNewOwner

    OldHouseNewOwner New Member

    Thanks Andy, cracking advice, appreciated.
  6. OldHouseNewOwner

    OldHouseNewOwner New Member

    Don’t suppose you do domestic in the West Midlands do you Andy?
  7. andy48

    andy48 Active Member

    'Fraid not. Pretty much retired and West London based.
    OldHouseNewOwner likes this.
  8. Dave does Gas

    Dave does Gas Screwfix Select

    There is a tapping on the cylinder for an immersion going by picture three, maybe you could consider having one fitted as a tempoary measure.
    OldHouseNewOwner likes this.

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