Washine machine water cold when it should be hot

Angilion · 5 Apr 2019 at 23:54

I have a Beko WTGB41B1W washing machine connected to the cold water supply.

Symptoms:

It's washing in cold water despite being set to 40C on the controls.
It's washing for the usual length of time in the usual cycle.
No error codes displayed.

My initial explanation is that the thermosensor isn't working and is reporting "correct temperature" all the time. If the thermosensor was working and the heating system wasn't, the wash cycle would stop forever as the machine is designed to wait until the correct temperature is reached before carrying out any washing part of the cycle.

Is there anything I can easily do to gather more information without opening the machine? I have a service contract on it, so I can just call someone out to fix it and I don't want to take anything apart. It's just that with my work schedule it's a PITA to have someone out for anything because I don't know what days I have off and I prefer to sleep as much as possible for most of them. So I'd like to be able to give them as much information as possible so they can be as prepared as possible before coming out.

darael · 6 Apr 2019 at 09:38

I'd say a dead heater element is your problem, less likely could be something faulty on the PCB.

Angilion · 6 Apr 2019 at 18:09

darael said:
I'd say a dead heater element is your problem, less likely could be something faulty on the PCB.

A dead heater element on its own should not cause these symptoms on this washing machine, assuming that the fault finding pages in the manual are correct and online DIY references to Beko washing machines are correct:

Angilion said:
If the thermosensor was working and the heating system wasn't, the wash cycle would stop forever as the machine is designed to wait until the correct temperature is reached before carrying out any washing part of the cycle.

Apparently that's how Beko washing machines are designed.

darael · 6 Apr 2019 at 19:24

I've never used a Beko machine, so I can't really say how they might normally operate. But it shouldn't be very hard to replace the thermostat and should be quicker to do that waiting in all day for an engineer.

Here is a video which may provide useful to you:

Angilion · 6 Apr 2019 at 21:26

That video was one of the things I looked at to confirm how Beko machines responded to a failed heating element and/or thermosensor - that washing machine had been stuck in the wash cycle for over 2 hours because it was waiting for the water to heat. I could do that fix, but I'd have to buy the tools and do the work that I'm already paying someone else to do. Which is more inconvenent - doing that or waiting in for an engineer? Six of one and half a dozen of the other. Also, I know have some more information that further complicates fault finding...

I decided to do a thorough cleaning of the washing machine, just in case. It's probably been too long since I ran the drum cleaning cycle because it takes so long (over 4 hours!). I always use the daily wash cycle at 40C, which takes 38 minutes. I had some washing machine cleaner, so I used that and used the recommended settings on the box - synthetics wash at 60C (which takes 2 hours 4 minutes), no washing inside, washing machine cleaning solution instead of detergent. Just to see what happens (I had a vague idea that maybe some buildup of something somewhere in the machine might be a factor, possibly) and also to clean the washing machine as a courtesy to whoever has to fix it if I use my service contract.

The glass of the door is now decidely warm to the touch, i.e. as expected when the drum is partially filled with water at 60C. The water is definitely being heated by the washing machine and the glass feels a bit warmer than it is on a 40C wash, so I think the water is at 60C. It's definitely being heated, so the element and the thermosensor must be working. Curiouser and curiouser!

When it's done, I'll run some clothes through at the usual 40C daily wash cycle and see if the water is heated.

NoobCannon · 6 Apr 2019 at 21:54

@Mr.Cookie

BigBoy · 6 Apr 2019 at 23:13

@OldCoals is/was a white goods repair man if my memory serves me correctly...

I would replace the element first then go for the thermostat.

darael · 7 Apr 2019 at 10:38

Angilion said:
I decided to do a thorough cleaning of the washing machine, just in case. It's probably been too long since I ran the drum cleaning cycle because it takes so long (over 4 hours!). I always use the daily wash cycle at 40C, which takes 38 minutes. I had some washing machine cleaner, so I used that and used the recommended settings on the box - synthetics wash at 60C (which takes 2 hours 4 minutes), no washing inside, washing machine cleaning solution instead of detergent. Just to see what happens (I had a vague idea that maybe some buildup of something somewhere in the machine might be a factor, possibly) and also to clean the washing machine as a courtesy to whoever has to fix it if I use my service contract.

The glass of the door is now decidely warm to the touch, i.e. as expected when the drum is partially filled with water at 60C. The water is definitely being heated by the washing machine and the glass feels a bit warmer than it is on a 40C wash, so I think the water is at 60C. It's definitely being heated, so the element and the thermosensor must be working. Curiouser and curiouser!

When it's done, I'll run some clothes through at the usual 40C daily wash cycle and see if the water is heated.

Do you live in a hardwater area? I'm wondering if perhaps limescale is the cause of your problems.

Get yourself a 250g box of Citrix Acid, from the likes of Wilko (link). I always put a whole box into the machine and set it away on a 95c cycle - if you have a "wash plus" or stained option that lengthens the wash cycle, use it to help ensure a thorough clean. Citrix Acid won't leave your machine smelling nice like most washing machine cleaners should, but it will ensure a very good clean out.

Angilion · 8 Apr 2019 at 00:31

darael said:
Do you live in a hardwater area? I'm wondering if perhaps limescale is the cause of your problems.

Get yourself a 250g box of Citrix Acid, from the likes of Wilko (link). I always put a whole box into the machine and set it away on a 95c cycle - if you have a "wash plus" or stained option that lengthens the wash cycle, use it to help ensure a thorough clean. Citrix Acid won't leave your machine smelling nice like most washing machine cleaners should, but it will ensure a very good clean out.

I do live in a hardwater area. Very much so. The washing machine cleaner I used claims to remove limescale too. My washing machine has the above option, plus an even longer "drum clean" cycle that takes well over 4 hours. Any wash cycle other than "daily quick wash" is impractically long.

I did a "daily wash" cycle at 40C (takes 38 minutes) afterwards. Cold. It was warm at one point, but not for long. The long 60C machine-cleaning wash I did also ended very cold, although it was 60C during the washing. It's not as it was up until about a week ago. The washing used to come out warm on a daily wash at 40C, now it comes out very cold. If it had been happening since I had the machine I would assume that the rinsing was done with cold water (which would make sense as an energy saving measure), but it's a change. The washing machine isn't connected to the net, so it can't be a change imposed remotely.

The washing is clean, but it's all very lightly used stuff so even a cold water wash with a detergent would probably be enough to clean it.

I'll be available during the day tomorrow, so I'll try a daily wash at 60C (takes 58 minutes) and check during the wash to judge temperatures. Then I'll get some citric acid from Wilko when I'm there on Tuesday, give that a go.

darael · 8 Apr 2019 at 18:54

Angilion said:
I'll be available during the day tomorrow, so I'll try a daily wash at 60C (takes 58 minutes) and check during the wash to judge temperatures. Then I'll get some citric acid from Wilko when I'm there on Tuesday, give that a go.

Post how you get on, but I feel sure the citric acid could help because you said you live in a hard water area.

Danthus · 8 Apr 2019 at 19:37

Elements either work or they don't, if you have an intermittent issue then it is almost certainly going to be a PCB problem.

Angilion · 8 Apr 2019 at 21:45

OldCoals said:
Elements either work or they don't, if you have an intermittent issue then it is almost certainly going to be a PCB problem.

I'm not sure that it is an intermittent issue because the outcomes are consistent. So far, it appears that the issue is with temperature sensing. If the thermosensor was reading too high, that would explain the results I'm getting. The element definitely works, so it's a control issue of some sort.

Mr.Cookie · 13 Apr 2019 at 04:17

Beko's have an inbuilt diagnostics (usually press and hold start/pause, whilst turning on with dial at first clockwise position from top)

It's been a while since we did beko but i'll see if i can find some info in the next day or so, just got back from two week hols.

Angilion · 13 Apr 2019 at 22:59

Mr.Cookie said:
Beko's have an inbuilt diagnostics (usually press and hold start/pause, whilst turning on with dial at first clockwise position from top)

It's been a while since we did beko but i'll see if i can find some info in the next day or so, just got back from two week hols.

Thanks for your help. I had no idea there was a diagnostic system built in.

I am now fairly sure that the issue is that the temperature of the water is being measured incorrectly. I've run washes and cleaning routines (i.e. empty and with stuff to clean/descale the machine and at higher temperatures) and the results are consistent - the cycle takes slightly shorter than expected, it completes normally, the temperature of the door during wash cycles is higher than when not in use or during rinsing and varies depending on the temperature set. With the temperature set to 40C, the bottom of the door (i.e. where the water is) is slightly warm to the touch. With the temperature set to 60C, it's quite strongly warmed. Given the current temperatures, if it was using cold water the door would be noticably cooled, not warmed. If the tenperature of the water was being measured as not reaching the set temperature, the washing cycle would never end. So I conclude that the element is working and that the temperature is being reported as being correct when in fact it's lower than it should be (but is being heated).

Work currently pretty much rules out having it fixed for a week or so more, but my washing is very lightly soiled and is coming out adequately cleaned at the lower temperature. My guesstimate is that it's about 20C under what it's set at.

Mr.Cookie · 13 Apr 2019 at 23:38

It's rare for ntc to fail but it can happen (90 percent sure bekos report an out of range sensor) and if it does machine may proceed through cycle without further heating.

Door glasses never feel as hot as people expect, some can be double skinned as well.

Modern machines use fuzzy logic in that programs will alter in time duration depending on temp of water coming in, speed of fill, speed of drain, ability of machine to balance load for spin.

Lastly and used to be quite common for beko is overdosing of detergent, they have a ball in the tub to sump hose (like a snorkel) which stops detergent from being wasted and clogging the sump up, but it does mean the machine is far more prone overdosing. This will upset pressure switch as the foam doesn't clear but water does on drain.

Will try to find any relevant info i can for your machine.