Tumble dryer heat pump problems

Discussion in 'Appliances' started by libby lou lou, 8 Oct 2017.

  1. libby lou lou

    libby lou lou

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    Hello, i have bought a hoover tumble dryer with a heat pump as a non runner,i.e. it runs but does not dry.. having took the front off, it's basically a fridge unit inside..finned rad, compressor. i 'm after advice on how to check the thing for refridgerent (sp) and what else to look out for, can any experienced person help i would be really thankful.....
     
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  3. If it's not drying the clothes, then it's the heating element that's gone. If it was heating the clothes, but not collecting the water, then it would be a post drum problem, either the condensor unit, or the pump.
     
  4. libby lou lou

    libby lou lou

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    heating element?
     
  5. Which model is it. Some condensor dryers work on the basis that the fridge element in for "condensing" the water in the hot air so that it gets caught rather than blowing out the back, but they still have a heating element in the first place.
     
  6. libby lou lou

    libby lou lou

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    thanks for your reply..this model DYH-9913NA-IX does not blow out the back nor have an heater...this is why they are so efficient......?
     
  7. I haven't come across one of these before, but as it's rated at 2300 watts, I suspect there's a heting element in there, that's suplemented by the heat recovered from the condensing unit. Sorry, when I said it blows out the back, I didn't mean as in a vented dryer which takes the hot wet air out; but the air has to go somewhere, somtimes out the front, and sometimes out the back, but in both cases, after the waters been extracted into the water resevoir.

    On the other hand, having had another look at this site, I could be wrong, and you could be right - for which I'd have to appologise.
     
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  9. libby lou lou

    libby lou lou

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    thanks.. please don't apologise, you tried to help... really need help at the moment...

    yeah.. that site..been there, not much help.... feel like i live on mars at the mo...
     
  10. Have you had a look at the site (highlight blue in the last post). Did the previous owners clean out both filters, as I've seen people throw things out because they didn't read the manuals. And it's got the instruction manual there as well.
     
  11. So you've cleaned both filters, and the drain hose isn't blocked, and the rooms above 7C. But this ones totally new to me, so it may well be that you need an engineers visit I'm afraid, as you could well be right that the heat pump isn't working.
     
  12. CarlH

    CarlH

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    We've decided against a heat-pump tumble drier for the same reason that we didn't go for the condensing type. We can use a vented drier with a very short exhaust duct because the drier backs on to an outside wall. The running cost is appreciably higher than that of a condensing one, and a lot higher than that of a heat-pump one. However, we have found vented driers very reliable, as well as far cheaper to buy than the more complex designs, and regular maintenance involves only keeping the air filter clean and, very occasionally, vacuuming out the exhaust hose via the external terminal. Leaving environmental concerns aside (which we cannot expect to keep doing for ever!), we are convinced that the lower running costs of the more sophisticated/environmentally more friendly designs are unlikely to offset the much higher purchase price over a normal tumble drier life of, say, 10 years (our current Bosch drier is 22 years old and still running as well as ever).

    We also reflect that the more complex the drier (this is more true of the heat-pump type than the condenser type), the more likely it is to need service visits, and more expensive such visits will be.

    CONDENSING TUMBLE DRIER

    Unless it has a cold water tank to create a cool environment in the condenser, this type of machine relies on the ambient air being cool enough for its air-to-air condenser to condense enough water out of the exhaust air to make this air only slightly, rather than very, damp. Our tumble drier location is in our utility room, which is a single story extension to the kitchen. Despite massive insulation of the flat roof structure, the room gets too hot in summer for a normal condensing drier to work well. The high ambient temperature in the room is increased by the central heating gas boiler which, even in summer, when the radiator circuits are off, heats our domestic hot water (dhw). We can avoid this by using the high or low level immersion heater in our dhw cylinder, which is, as usual, remote from the boiler. However, although the boiler works inefficiently with only the load of heating the dhw, the cost of water heating is still MUCH greater with electricity, so we still use the boiler except in VERY hot weather.

    There is the added concern with a condensing tumble drier that not only is the air that it exhausts into the room where is is located still warm, but it is also still damp, and, however good the air filters in the drier, dusty. Also, again if the air filter is not very effective indeed, moisture in the warm damp air that does condense out in the condenser is dusty air, and some of that dust is deposited, with condensed moisture, onto the condenser heat exchanger. So, compared with a basic vented drier, there are two extra chores: regular emptying of the condensate tank, and occasional (?) cleaning out of the fluff-filled condenser - or so I read.

    HEAT PUMP TUMBLE DRIER

    This is basically a condenser drier with a heat-pump-operated heat recovery system, which allows the amount of electricity needed to heat the incoming air to dry the clothes to be MUCH lower than with a basic vented or condenser drier.

    Because the heat pump uses, like a fridge or freezer, a vapour-compression circuit to chill the exhaust air from the drum (and transfer a high proportion of that heat energy to pre-heat the air drawn into the drum), the rate of efficiency of condensation should be much less sensitive to ambient temperature - though some machine specifications advise what sounds an unsuitably narrow band for ambient temperatures.

    For an installation where it would be impossible to use an externally-venting drier, the basic design of the heat-pump machine is obviously a lot better than that of a simple condenser one. However, the following objections still apply, at least in our case:-

    1. Exhaust air will still be warm, though less likely to be unacceptably so except in hot weather.

    2. Exhaust air will still be dusty. It is not realistic to expect a level of filtration which avoids this completely.

    3. The condensation compartment, where the warm air ex the drum passes through the very cold EVAPORATOR of the vapour compression circuit, will gradually get clogged with dust and "lint", and may be awkward to clean.

    4. There is still a condensate tank to empty regularly.

    5. The machine is so complex that unfailing reliability over many years of service may be difficult to ensure, and servicing will be expensive.
     
  13. opps

    opps

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    We recently went from a vented machine to a heat pump Hoover. The new machine uses much less energy (per hour) but takes 3 times longer to dry the clothes. Oh and we have to empty the water container in the door pus two sets of filters.

    The new tumble drier cost over £500 (but hey,it's Wifi enabled..). The old one was 21 years old, cost about £200 when new. Admittedly the bearings were wearing out but total cost of ownership was £200 plus a new belt and two heating sensors, ie £200+25.

    Were it not for the fact that SWMBO decided to ditch our bespoke kitchen and replace it with a crap off the shelf kitchen we would still have our 21 year old fridge, freezer, tumble drier and Miele washing machine.

    Our integrated fridge is about 15% smaller than the old one and 300% more expensive. The freezer is 27% smaller and again about 300% more expensive. The washing machine is marginally cheaper and roughly the same capacity (but a Siemens).

    Sorry, am going off on a rant here... I hate our new kitchen and the fact that I am going to be the sucker that has to try to fix the overpriced appliances when they fail, which I expect will be in the next 5 years or so.
     
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