Gaggia TS Leaking Steam and Hot Water Tap Washer Replacement

Once Christmas was out of the way, I had a plan to descale the TS, hopefully to cure an occasional problem with scale blocking the pipes (more of this in a future post).  But the machine got the better of me and began dripping from the hot water tap, filling a cup in about an hour.  Time to get the taps apart and investigate.

First to come off are the front panel knobs.  These should just pull off, but the steam one was stubborn.  A bit of levering with a screwdriver….

…and it snapped off.  Nothing that the hot glue gun won’t fix later.

With the remnants of the knob removed, the nut bit on the front panel can be removed.  Use two good spanners to prevent damage to the pipework.

Continuing with the tap, loosen the copper tubing connection.

Both the steam and water taps can be removed with their spouts still attached.

Using a pair of spanners again (or better still a vice) loosen the pipe connection from the rear of the valve.  Undo the final turns of the nut by hand and be ready for it all to fly apart under spring pressure.

In my case the cause of the leak is the perished washer.  You can turn these over and reuse the other side, but you will be back here in a year replacing the washer as they become brittle over time.

Hold the body in some grips (protecting it from damage with a cloth) and loosen.  If the thread breaks at this stage, a new tap will be required.

This is what it looks like when the old washer has been levered out.  Obviously, when putting it back together, just nip it up.  It will be so much easier next time.

Scale can build up on the ridge where the washer sits when the valve is closed.  Carefully remove it with a blunt tool, or soak in descaler.

This pintle sits between the threaded control knob shaft and the washer carrier.  Soak in descaler if required and lubricate with silicone grease before refitting.  It should move freely in the brass tap body.

Here is the detail of the Gaggia TS Steam wand, if your machine has the basic panarello milk frother, this is a must do mod.  The steam power is almost unbelievable in comparison.

Putting it back together is the reverse of disassembly.  Flush through both of the taps to remove any debris, and check for leaks on the pipe connections before replacing the lid.  I had to glue the knob back on, which was straightforward with the hot melt glue gun.

We stock the TS wand, spare washers, taps and knobs to buy online if you need them.

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50 Responses to Gaggia TS Leaking Steam and Hot Water Tap Washer Replacement

  1. Tim Hedlund says:


    Thanks for a great blog! 😀

    Today I put together my Gaggia TS. After a complete disassembling, with decalcification and cleaning.

    Everything seemed fine until I started, puff … The fuse went …

    Tried to pull out a small spike at the thermostat to the immersion heater, and then the machine worked. (started to fill up) But no power to the immersion heater. Do you have any reflection on what might be wrong?

    Kind regards Tim Hedlund!

    • admin says:

      Hi Tim,

      I am not sure what you mean by “spike at the thermostat”.

      Can you please explain this bit in more detail?


  2. Tim Hedlund says:

    Look at this picture:

    I think is a reset button for the thermostat. When it is in closed position the pump operates (and the fuse is fine), but not the electric heater. (cold)

    Perhaps immersion heater took damage when it was in the descaling water … :/

    • admin says:

      If I am correct, the safety thermostat is on the neutral side of the element, meaning that when it is open, the live feed runs from the main inlet, through the controller, through the pressurstat, through the element, and to one side of the safety thermostat. Therefore, it appears there is no fault to earth which would take out the fuse (assuming your mains lead is wired correctly).

      When the safety switch is closed the fuse blows. This appears to be due to overcurrent from live to neutral. I don’t think this would happen due to descaling.

      The facts fit the case where the mains is wired so that the live feed enters the safety thermostat, then runs to the element, and there is a short from that short piece of live wire, or the element coil to earth. Descaling is unlikely to result in a short allowing enough current to blow a fuse (it will trip an RCD though).

      Can you give me some more information? Have you disturbed any wiring? Has it ever worked? Do you have a multimeter, and where are you in the world?


  3. Tim Hedlund says:

    I did some research now. I switched on the thermostat and pulled out the wires to the electric heater. I measured the cables and there was power. (see picture)

    My theory is that the electric heater may be broke when I had it under water (descaling). Do not know if it is sensitive to drown in water?

    Everything else works … Pump, heat the brew head, filling relay, brewing button, level adjuster, control box … There must be a problem with the electric heater :/

    I live in Sweden, I I have a multimeter (see picture below) Everything is connected as it was before I disassemble the machine. And then everything worked without problems.

    // Tim

    • admin says:

      With a multimeter this should be easy.

      You have 230V AC at the terminals for the element, as expected.

      With the multimeter on ohms, now make the following measurements:

      1. From one end of the element to the chassis.
      2. From the other end of the element to the chassis
      3. Between the two ends of the elements

      Can you let me know these.

      It is conceivable that the descaling has removed the scale and penetrated a crack in the element. I have had this, and it was sufficient to trip the RCD.

      I don’t suppose you disconnected the element when descaling did you (just wondering if you connected the power to the earth tag on the element by mistake)? Unlikely I know.


  4. Tim Hedlund says:

    Hope this is correctly:

    1. 0.507 ohm
    2. 0.507 ohm
    3. 36.8 ohm

    I had everything in a bucket with Cintron acid and water in a few days.
    I disconnected the electric heater as it was linked before, when the machine worked.

    • admin says:

      From your measurements, there is an element fault.

      As you say in your later post, P=V^2/R, so P=(230*230)/36.8=1437W in the element, which is expected.

      But there is only 0.5 ohms to ground. This would result in a very large current through the live and is the cause of the blowing fuse. A 0.5 ohms resistance would result in 230/0.5=460A flowing (assuming no other resistances in circuit). I would expect the normal resistance to be much higher for readings 1 and 2 (greater than 500k ohms). You might want to double check your readings.

      I would inspect the element closely, to see if you can see the cause of the fault.


  5. Tim Hedlund says:

    By my calculations, should that be good, (?) at least between the terminals :/

    R = (230 * 230) / 1400
    R = 37.7 ohms

  6. Tim Hedlund says:

    I do not really know what to look for .. Is it time to order a new immersion heater? Should be the only fault huh?

    // Tim

    • admin says:

      Did you put the whole element in the descaling solution?

      If so, the element is insulated from the copper sheath with a chalky mineral. That would have absorbed the descaling solution and certainly would short the element to earth.


      A long period in a domestic oven “might” dry it out. You could monitor the resistances measured from the element to ground to see if they improved.

      I don’t know of a supplier of spare elements.


  7. Tim Hedlund says:

    Unfortunately, I dipped the entire heater in the water … I’ll try your tips!
    Otherwise I buy a new one. Have a good provider here in Sweden 🙂

    I will come back with results!

    Again thanks for your help …!

  8. Tim Hedlund says:

    I have now had the electric heater in the oven for a few hours. And measurements options seem quite different 🙂 (Have also measured with the electric heater mounted in the boiler, the same values)
    (First the measurements rise to about 30.xxxx, then go slowely down again: s A multimeter might work that way?)

    I happened to crack one porcelain knob when I would take out the immersion heater :/ But not it will interfere with the performance too much?
    Will try to plug it in when I get home, keep our fingers crossed 🙂

  9. Tim Hedlund says:

    I tried today but the fuse blow … : (

    Time to order a new immersion heater?

  10. Tim Hedlund says:

    I tried to connect one of the cable (live, red) plugged in, but the fuse blew again :/

    I’m very careful, do not touch anything during these tests! (except the switch)

    Thanks for the tips! Will see what I get price here in Sweden 🙂

  11. Tim Hedlund says:

    I have now ordered a new immersion heater. I hope this solves my problem! I had to pay about 75 € for the heater 🙂

    I retur with results!

  12. Tim Hedlund says:

    Hello! 🙂

    I finally got my immersion heater, now everything is working perfectly!

    Thank you very much for your help …!

    Kind Regards Tim Hedlund

  13. marko says:

    Random question for all you TS owners – does anyone know the size of the thread on the TS steam wand fitting?

    I’ve got a Gaggia Achille that I want to install the TS wand on, but not sure whether it will fit correctly or whether an adaptor might be needed.

    Thank you for your help!


  14. andrew says:

    Hi how can I purchase the steam wand for the gaggia ts off your website as stated in the last paragraph of this blog?

  15. Rui Bastos says:

    We have no Gaggia agents in South Africa for the commercial machine. Can you please tell me were I can purchase the tap washer seal, looking for 3 knobs and the seals that fit above the portafilter. Really would like some help.

  16. Boris says:

    Do you know if the steam wand nozzle is removable? I find the 4-hole hard to use for small quantities of milk and would prefer a 2-hole.

    • admin says:


      I don’t know, but think it is not removable.

      I would fill two of the holes with food grade silicone, to leave two for steaming.


  17. Gerry says:

    Hi Steve,
    I wonder if you can point me in the right direction please.

    I’ve picked up a 2004 gaggia TS which seems barely used, I know it’s sat for several years in storage.

    The machine all appears to work as it should other than;

    1. The steam wand remains open so to get the machine up to pressure i’ve held a cloth over the nozzle to stop steam escaping! Is there a quick fix I could try ie. tightening something or do you think a tap rebuild kit would do the trick or something else please?

    2. The hot water tap was stuck closed with zero water coming out, it took a spanner to unstick the knob shaft, now the water flows but when the tap is shut there is a small regular drip
    Thanks for your anticipated help.
    Kind regards


  18. Gerry says:

    Yes Steve that’s exactly where i’m at, I guess I will just have to try and borrow a couple of larger spanners tomorrow and eat three wheatabix before trying to tak them apart again.

    I very much appreciate your help.


    • admin says:

      I think with mine, I had the spanners nearly 180 degrees apart, with the valve on an offcut of wood. That way I could use my bodyweight to benefit and apply maximum force.

      The joint just then “gives”.

      Good luck.


  19. Gerry says:

    Thanks again Steve,
    Both taps fully stripped down, descaled, replaced and working perfectly.

    Unfortunately I am asking for help again please as there is another fault which wasn’t apparent when the taps didn’t work!!

    The machine gets up to 1.5 bar and then after a while starts to fall to the point that there is almost zero pressure. The boiler is still hot and seems to be still heating but that may just be that it hasn’t cooled down enough for me to notice any change.

    If I switch the machine off for a few minutes the boiler heats and the pressure rises to 1.5 bar and as before it can pour a shot or produce plenty of steam but once the pressure is reduced it won’t increase again without me switching the machine off and on again after a few minutes which my well be enough time for the boiler to cool marginally?

    Any ideas very welcome and if it needs a part that you stock please please direct me to that as i’m without an espresso machine at the moment which is making me very unpopular with my wife and kids.

    Kind regards


  20. Gerry says:

    Wow! That was the quickest reply I have ever had on the internet.
    Thank you again Steve, have you thought about adding a paypal donation button to your blog, I would certainly donate the price of a pint.

  21. Gerry says:

    Hi Steve,
    The pressurestat arrived today, thanks for the swift delivery. Unfortunately as i suspected that wasn’t the problem (I had checked and there was 240V at both sides) but I wanted to try anyway as the one fitted was a few years old and I couldn’t hear it click so at least the machine has a new one now!

    Anyway, before I plough more money in to this and replace the controller I wonder if you could help again please?

    1) I’m assuming that where you say on your blog, “If it appears there are volts at the pressure switch output, and the overheat thermostat is closed, then the element is at fault.” it only applies where the boiler isn’t heating up the water?

    2. I’m wondering whether repairng the Gaggia is a false economy as the controller is so expensive and whether to sell it without the repair and let someone else sort it. Do you have any idea if there is a market for the machine and what one in good overall condition in full working order and one in the same condition needing a repair might sell for please?

    3. And finally, having followed the links that you provided and carried out all of the tests, could this be something else or is the controller a very safe bet now?

    Thanks again

    • admin says:

      It could be the element open-circuiting when hot or the controller.

      Monitor the voltage on the pressure switch side connected to the controller.

      When the element stops heating (when it SHOULD be heating) check the voltage.

      If the controller is supplying 230V to the pressure switch and the pressure switch is supplying 230V to the element, then the element should be heating the water. If not the element is faulty.

      If the controller stops feeding 230V to the pressure switch, then check the controller further. The element is probably fine.

      Check the red light is not on on the front panel (ON means water tank empty). Check with the boiler top sensor disconnected, the machine tries to fill the boiler.

      With these two checks done, it will be the controller. This is the most common fault on the TS.

      Don’t change anything else until you are sure it is faulty. The controller and element are about £85 each.


      • Gerry says:

        That’s very helpful Steve,

        The machine gets up to working pressure and then after a short time the voltage from the controller to the pressure switch drops to zero, occassionally it returns and then cuts out again but generally it stays at zero. I switch the machine off to cool it down and then when I switch it on the same cycle happens.

        There’s plenty of water and no warning light on, the pump kicks in when I disconnect the boiler sensor and stops again when i reconnect, I’m guessing that this means it’s a sensor fault. Is there anything I could try to repair the sensor or is it a straight swap for a new one?

        Tracing the wires from the pressure switch to the controller and the element was a surprise, they were the wrong way around on the pressure switch which has been the case since I bought (I marked them before removing them) so it’s possible that the person that sold it to me has tried unsuccessfully to sort out the fault!

        Many thanks.


        • admin says:

          The pump should kick in when the boiler sensor is removed.

          The wiring can be connected either way to the pressure switch, it will make no difference.

          The fault is 99% likely to be the heating element relay in the controller.


  22. Gerry says:

    I realised that the pump should kick in, the structure of my sentence didn’t make that clear though, I didn’t realise that the wiring could go either way around to the pressure switch but it makes sense.

    Thank you for all of your help, I’m sure that I’m on the home straight now and will have a working machine again shortly.


    • admin says:

      Are you up an running with your machine now?

      • Russell says:

        Hi Steve
        just like to introduce myself and let you know that I have “taken up the baton” as it were from Gerry having bought this machine from him.
        In answer to your question “are you all up and running” the answer is… Almost! It’s all running fine now having had new stat and controller, plus Gerry refurbed the taps.
        But I (Gerry also) have had a problem steaming milk. My first thought was it may be water level possibly to high and not enough steam in the top of the boiler? So I soaked the boiler probe and the anti suction valve in descaler refitted everything and the boiler pressure started shooting up from previous 1.3ish to 1.5-1.6 bar… Great! So I tried steaming again and it has gone from quite dry steam as It was when I received it from Gerry to now quite wet steam, fine water dripping from steam tip while steaming? The anti suction valve was spitting out a lot of water on reaching temp and a bit leaky when it closed off so I have ordered a new one from you and also plan to give it a descale. I have split a few joints in the pipe work to check and there does not seem to be any scale, in fact strangely very clear, must be originally from a soft water area?
        Regarding the descale I would normally just mix citric acid in the water tank run some through, switch off and leave it to stand for 20 mins, then run some more and so on every 20 mins then flush through with water at the finish. But Is this the same for HX machine or should I do something different?
        Many thanks

        • admin says:

          Hi Russell,

          Once you have replaced the anti-vac valve, I would draw off some hot water, and then allow the boiler to fill back again.

          Hopefully the steam will then be drier. You could also consider a longer probe I guess, but I have not come across this problem before, so hope it is only the antivac.

          With the HX, there are two water circuits, the main boiler and the heat exchanger path to the group.

          Because of the capacity of the boiler, I would be tempted to empty the boiler (syphon out of the probe opening) and then fill it with the descaler solution.

          I would also pass a small amount from the tank through the group head. In fact I would do this first, then at the end drain the boiler and give it a goo flush with clean water.


  23. Russell says:

    Hi Steve
    I think we are making some progress with the steam… The new anti-vac valve arrived thanks Steve, In the end I just fitted the valve to machine with no descaling and there was a noticeable difference in the way machine warmed up… Cant put my finger on it but it just seemed to sound different and seemed to be boiling for longer? I also had to reduce the boiler pressure as well. Anyways new valve gave a tiny little spurt when it reached temp and shut off with minimal dribble. The steam was a lot drier but seemed more powerful. I practiced with some water and couple drips of Fairy liquid.. see youtube for that one. It wasn’t brilliant but better than anything so far. So then I blanked off two of the holes on the tip with snapped off cocktail stick ends and hey presto we were getting really close to some microfoam! I’ve not tried it with milk yet…
    So that’s where we are and I think I’ve got to try and get a two hole tip from somewhere?! Or a new smaller holed 4 hole? The holes on this tip seem massive when you compare with my tip with other tips online?
    The tip was removable on mine (not always the case I believe)? and measuring by eye it looked about 8mm, do you know if it is 8mm for sure? Are the tips on the one’s you sell removable? I need something as a guide so I can order a tip from somewhere?
    Steve can you point me to your email address so I can send you a pick of my tip to see what you think? Does that sound rude?!

    • admin says:

      You can find our email address by clicking the following link (avoidence of spam):

      I don’t know the thread size as the wands I have don’t have (easily) removeable ends.


    • admin says:

      Hi Russell,

      The tip on my machine looks similar to the photo you emailed.

      I just cleaned out the milk holes with a 1.5mm drill bit. The holes are a little bigger than the drill, but definitely below 2mm. I would say 1.6mm diameter.

      By the way, in the video link it looks like around 200mL of milk.

      In the interest of comparison, I just measured 200mL of full-fat milk from the fridge, and with the steam pressure indicated as 1.5bar, raised this from 10degC to 70degC in 10 seconds.


  24. Russell says:

    Hi Steve
    I just emailed you again…. I’ve ordered new tap kits from you… seems that it’s water in the steam!
    Will keep you updated

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