Heating issues?

Discussion in 'Plumbers' Talk' started by R Mills, Nov 23, 2021.

  1. R Mills

    R Mills Member

    Hi all, bit of a wired issue here!

    So I rent my house, moved in April and we've had nothing but issues with the heating. In my landlords defence, we have tried every plumber to get this heating sorted, but they all dont reply, don't understand the system, or are to busy.

    So basically the heating gets stuck on, at first plumber wanted timer/control unit fitted as it was wired up DIY style with light switches. This has since been changed to a programmer for hot water/heating. The same problem persisted, so the plumber has decided it needs a new three port valve in the room with the tank, he's coming in a few weeks!

    When I say it's stuck on, it ignores the stat, ignores the timer/programmer and will just stay on and boiler will just regulate the water temp.

    Anyway now for my current problem, we had below 1c last 2 night and now I can't seem to get then house warm, the heatings on, radiators are absolutely burning hot, but downstairs won't get past about 16c, other than the kitchen. Upstairs isn't a million times better but I am able to get closer to 19.3c. Is there anything I can do about this whilst I wait for the plumber?

    When house is warm, it usually holds heat quite well, only dropping 2-4c overnight.

    Double glazed throughout (some windows are blown, but not in the living room or the bedroom I'm checking). There is loft insulation but it looks older. House is approx 1986, possibly original! I assumed this wasn't it since it holds the heat but I don't know. All the radiators are singles unvented, accept the one in the kitchen, hense this room is hotter as I think this is the only new radiator since house was built.

    Some of the radiators, especially the living room (2 big 2000mm radiators) don't get warm at the bottom for over 3 hours, but then they start to warm up. So I know there's dirt in the system, will this make that much difference?

    Any suggestion would be great, thank you

    Attached Files:

  2. R Mills

    R Mills Member

    To add, radiators are all burning hot at top, all are a little cooler at bottom but downstairs ones seek considerably worse. I believe it's a gravity system not a pressured one.

    Boiler is on approx 75c water, it's just a dial so it's a guess, but if I turn it all the way up to approx 85c, it really makes no difference to the house heat
  3. Teki

    Teki Screwfix Select

    If you turn down the radiator valves of the ones that are getting very warm, it may allow the others to get warmer. If they are still cold, try closing all the radiator valves fully except the ones that don't heat up.

    Have you bled the radiators recently? When you do, is the water black?

    Are you able to check the state of the water in the small F&E tank (usually in the loft)?
  4. R Mills

    R Mills Member

    Firstly, thank you for your reply!

    All of the radiators up stairs, I have turned both valves down to approx 1-2 turns (there's no trv so I just do both sides), and the two big living room ones still get bruning hot at the top, and cold at the bottom for hours.

    I tried bleeding them as when heating first comes on, you hear water filling the radiator in the main bedroom! But no air came out of any of them (3 bedrooms, a bathroom, 2 living room, 1 kitchen and one front room/converted garage). Water is slightly darkened but very very slightly, not significantly.

    The tank in the loft looks amazingly clean all things considered, there's clearly a bit of sludge in the bottom, but I'd say it looks less than 1 handful of sand quantity.

    I would assume the system was drained last year, the February 13months before I moved in the downstairs flooded about 2 foot deep (road flooded from river/stream), so I don't know if they would have drained the system then? I've not asked. I know it had new plugs and fuse box.

    But I'm 99% sure the radiators have sludge in bottom, because all of them are slightly colder at bottom, but it's just the big two in living room that the bottom are awfully cold!
  5. Teki

    Teki Screwfix Select

    The system should have been balanced by adjusting the lockshield valve on each radiator. If possible, you shouldn't touch that one. At least you counted the number of turns so that is useful to help you reset them. It is the wheelhead valve you should adjust or turn off.

    Sludge is a possibility however, it depends how much you want to try and resolve this yourself?

    You could speak to the plumber and add Sentinel X400 to the F&E tank and ask if it can be drained in a few weeks at the next visit?
  6. R Mills

    R Mills Member

    When I moved in, it appeared the last tenant has opened both valves on all rads all the way, so it wasn't balanced at all to start with! Some radiators have covers both sides, some don't have one either side, so I have no idea which side is locksheild. All pipe warm fast, there microbore pipes.

    I did hear about this stuff, I didn't know if the plumber would be willing to try that because of th microbore pipes, from reason, people are sceptical with them. And all 4 radiators down stairs would have to be drained, as there pipes go upstairs separately
  7. Jimbo

    Jimbo Screwfix Select

    Does the house meet the EPC requirements for rental properties? Domestic private rented property: minimum energy efficiency standard - landlord guidance - GOV.UK (www.gov.uk)

    It sounds like the problem is essentially downstairs radiators with insufficient flow and this can be resolved by fully opening both valves on all the downstairs radiators and closing the lock-shield valves on all the radiators that do get properly hot half a turn, monitor that for a few hours and then repeat until even. It's normal for some radiators to be almost completely closed (maybe open 1/4 to 1/2 turn only) that are closest to the pump. Once they are all heating evenly if the surface temperature is then not adequate (i.e. cold in the middle) then the next thing to try is increasing the pump speed, usually there are three settings. But, be very careful to check for 'pumping over', which is where water is pumped through the expansion pipe and drops back in to the expansion tank. This is very bad since it aerates the water (like a fish tank!) and will quickly destroy the entire system.

    Chemical cleaner is very likely worth a shot, I prefer Fernox F3 as this targets more than just sludge in the system. Is there a magnetic filter next to the boiler, possibly a black thing labelled 'magnaclean'? If so cleaning that will give a good indication of the build-up elsewhere. Otherwise, once chemical cleaned ask the plumber to fit one.

    Finally, if you take some water from a radiator, what colour is it?
  8. R Mills

    R Mills Member

    Thank you for your reply!

    So my EPC is apparently due to expire in the coming months, but house is overall rated C, as it has double glazing, insulated loft, insulated walls, it seems to have been marked down on heating controls, down to very poor infact!

    The downstairs radiators all have separate pipes coming to them from upstairs (none are loope or whatever), I've fully opened the 2 in living room the one in the converted garage is small, it doesn't seem to have a colder bottom. Kitchen one is newer and again seems fine, it's just to two massive ones in the living room I think!

    The pump has been on speed 3 since I lived here, I actually considered turning it down to save electric but thought, I better not touch it

    Finally I can't see a filter anywhere, as my landlord said he was unsure if one was fitted and to check, so I've been looking online and going around house looking for one, none that I can see (although next to the boiler there.is a wooden cornering covering pipes, if it's in there I can't get.to it)
    Thank you
  9. Jimbo

    Jimbo Screwfix Select

    In that case start closing the lock-shields of all radiators that do heat well half a turn until even.
  10. Kas228

    Kas228 Screwfix Select

    Sounds like the system/radiators needs correctly balancing and a good clean out. If the radiators nearest the boiler are fully open on both ends it is going to have a big impact on other rads in the run particularly those furthest from boiler.
  11. R Mills

    R Mills Member

    Okay I will try to balance it again, have tried it before when I realised shields were open!

    I don't actually know the order of the radiators, as the 3 port valve is in a cubbard in the central of the house, typically!

    And if I was to add these chemicals to the system, how soon do they have to be drained? And what happens if they're not drained soon? I will call the plumber tomorrow but doubtful he will fit it in when he's changing the 3 port valve in 2 weeks :/

    The heating can be on for over 4 hours and the bottom of the living room radiator can still be Luke warm at best (last to heat, but pipes are hot same time as others so I assume it's clogged)

    Thank you
  12. Mike83

    Mike83 Screwfix Select

    If the 3 port is faulty then a large amount of the circulating water might be going through the cylinder coil.
    This wound hinder any balancing efforts.
  13. R Mills

    R Mills Member

    It's believed to be.

    Basically no plumber would touch the system til it had a programmer/timer fitted because at some point (prior to my landlord purchased apparently), they broke and just switches were put in place.

    Now they're changed and that didn't fix the problem, they are saying it's the three port.
    Hot water works
    Heating works, comes on when you want, within the first couple of minutes you can turn it off, after that it's jammed on, it ignores the stat, ignores the programmer/timer. Boiler just keeps going unless you turn the water temperature down, and them when waters at that temp it will them keep going. Have to shut off entire system for like 12 hours or so, otherwise when you turn it on, heating comes on
  14. Teki

    Teki Screwfix Select

    If you use Sentinel X400, it can be left in the system for a few weeks or longer with no detriment. It holds the sludge in suspension. How long you leave it in there will depend on how often the heating is used.

    It's best to have a Magnetic filter fitted though if you don't have one already.
  15. R Mills

    R Mills Member

    Thanks all for your replys.
    Last night I made sure the entire system is balanced as well I could, all upstairs radiators are within 1/4 to 1+1/2 turns (2 of them are 1600mm rads).
    I left the two in living room completely open, they still are Cole at the bottom. If I put the heating on, the bottom is cold, currently it's been on 7 hours (non stop heating water to temp), and as of current, the bottoms of the two living room radiators are hot, but by no means are they 'burning to touch' unlike the tops of them which you can't hold for more than a second (heat gun says bottom is 24c, top is 66c)
    I will wait for the plumber, if not I will try the recommended product and flush it myself.

    Is it likely because there big rads the bottom doesn't heat up? Im also going to mention to the plumber about a magnetic filter when he comes. Thank you all!
  16. Jimbo

    Jimbo Screwfix Select

    It sounds like they need more flow for sure. Is the pump on max?
  17. R Mills

    R Mills Member

    Sorry just seen this message!
    Pump is on setting 3 (max).
    The rads are heating up a bit better at bottom the more it's been turned on, but the return pipe is only slightly warm now, thinking maybe some crud moved.

    Not sure if I've mentioned it's 8mm microbore piping. But I am I'm a very soft water zone

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