Steam Boiler not heating up - pumps cold water but won't the boiler never heats up, I suspect the thermostat or solenoid

First, I'm not a Gaggia representative.
* Check your warranty. Call for service

*** The following is for information only. ***
* Larger espresso machines use a solenoid or valve to allow steam (under pressure) to exit out of the steam wand. (see below for my links on how to change these types of solenoids.)
* Smaller table top home units use a small vibration water pump (ULKA) to pump water into a preheated boiler.
* The boiler is kept hot (takes about 3-5 mins to heat up.) then water is pumped in to the open heated chamber. Steam is forced out the exit port.
* Sometimes (after long use) the boiler or wand may clog up and introduce a back pressure to the pump. This may cause a failure in the pump and the seals. (no steam from wand but lots of steam coming from the unit housing.)
* To repair the smaller units requires the replacement of the pump.
* The boiler should also be check for clog or bad heating element.
* Check the boiler themostat (regulates the temperature)
* Check the boiler High limit.(prevents fire if boiler overheats.)
* Larger machine; Gaggia steam wand change out; https://www.youtube.com/watch?v=OWoNXAq2Kus
* Auto froth upgrade review; https://www.youtube.com/watch?v=43qcuF3CP2o
* Steaming issues; https://www.youtube.com/watch?v=UoC7lLnlQz8
* ULKA pump repair; https://www.youtube.com/watch?v=DoO9ckyJ-rs
* Pump replacement; https://www.youtube.com/watch?v=HTm6dwJdn_4
* Boiler (Saeco); https://www.youtube.com/watch?v=SYSLajlUmHM
Aloha, ukeboy57

Additional info;
* Group cleaning; https://www.youtube.com/watch?v=6L5zufsA3-c
* Digital problem; https://www.youtube.com/watch?v=VViBcE6VvEw
* How to froth; https://www.youtube.com/watch?v=bvmILm1OLeI
* ukeboy57 - steam tip styles and cleaning; https://www.youtube.com/watch?v=P8L1hIQ2M6g
* ukeboy57 - Group Valve (similar to steam valve); https://www.youtube.com/watch?v=aJ3F5-bZZQk
* ukeboy57 - Group/Steam valve coil ; https://www.youtube.com/watch?v=aJ3F5-bZZQk

First, I'm not a Miele technician, but I've worked on similar table top espresso machines. But I suggest you contact your vendor for service. Check your warranty.
*** Following is just for information***
FYI; There are quite a few you tube videos on this machine.
* These smaller units have individual heaters and mini-boilers instead of one big boiler used in commercial machines.
* I suspect the steamer is a mini-boiler that are common on small brewers. It's about 3" x 4" and 1" thick made of aluminum. There is a heat limit fuse and thermo disk. One or both may be blown.
* If your getting sputtering cold water from the steam wand then it's definitely the boiler other wise it's the vibration pump. Quite a few vids on you tube about the ULKA water pump (suggest alexis c vid)
* I don't think there is any solenoid steam valve on this unit as it's only used on larger boiler systems where the boiler is under pressure all the time. The slow steam start is a good indication of the mini-boiler reheating.
* Final; This is a very compact machine with a lot of wires. Please review the vids on you tube by searching "Miele CVA 4070" Suggest getting help from your vendor as you will need those parts as mentioned.
Aloha, ukeboy57

PS there is a lock out feature on this brand. Check this link for more info:
https://www.bing.com/videos/search?q=Miele+4070&&view=detail&mid=87B4106BEC0DAF1D524587B4106BEC0DAF1D5245&rvsmid=9D76B03F2F848C9C94B59D76B03F2F848C9C94B5&FORM=VDQVAP

Don't know your specific unit, but in general, heating systems are two-stage devices:

1: Its too cold: the motorised HW/CH valve moved to the required position, and on achieving it, the circulaion pump starts and the boiler is enabled. (The circ pump may start immediately - its not usually important.) The hot water from the boiler circulates through the heat exchanger and/or radiators until the thermostat thinks its target is warm enough, whereupon it disables the boiler, stops the pump and closes/relaxes the valve(s).

2: The boiler is off while disabled. When enabled, it heats the circulating water to a 'high' temperature and seeks to keep it there. If it reaches that temperature, the boiler will cycle on and off as necessary to maintain the set 'high' temperature. (The circulation pump must run all the time the boiler is enabled.) This may be what you're noticing. Additionally, some boilers will run the circulation pump for a little while after being disabled to reduce the temperature if the water in the pipes and boiler.

Your question doesn't say how the pump running corresponds to thee thermostat settings, but if it were stuck on, I think you'd know!

Hi There is a reset button inside on the front side of the boiler (you have to take the top of the machine off. There are 4 screws and remove the water tank). It is located between 2 black wires and is a red button. Push it in and test. There is also another problem that you might have. If the brew thermostat is bad it won't heat. To test for this, push the steam switch and wait 15 seconds. Then open the steam knob and push the middle button and see if the water is warm. If it is then you need a new brew thermostat. That is the thermostat that has the red dot on the top. It sets on top of the boiler next to the steam thermostat. If you take the top off, make sure that the machine is unplugged. If none of these things work check the heating element with an ohms meter. The reading in the terminals should be from 12 to 16 ohms. If no reading the elements is bad and you have to replace the boiler.

There should be a control called an aquastat that regulates the temperature of the boiler. The thermostat will turn on the circulator to start the flow of water through the radiators. If the water coming back from the radiators is very cold, a control will shut off the circulator until the boiler can come up to a predetermined temperature then start the flow of water again. If you have a tankless coil for domestic hot water, you now have a triple aquastat that maintains the temperature for domestic as well as the boiler temp. So yes the boiler thermostat (aquastat) does control the heat of the radiators and domestic hot water. No the pump is regulated by your house thermostat. You should take an amp draw on the boiler and componants to find out what is drawing more electricity than it should and popping your fuse.

HI
If your lucky.
There is a reset button inside on the front side of the boiler (you have to take the top of the machine off. There are 4 screws and remove the water tank). It is located between 2 black wires and is a red button. Push it in and test. There is also an other problem that you might have. If the brew thermostat is bad it won’t heat. To test for this, push the steam switch and wait 15 seconds. Then open the steam knob and push the middle button and see if the water is warm. If it is then you need a new brew thermostat. That is the thermostat that has the red dot on the top. It sets on top of the boiler next to the steam thermostat. If you take the top off, make sure that the machine is unplugged.
If none of these things work check the heating element with an ohms meter. The reading in the terminals should be from 12 to 16 ohms. If no reading the elements is bad and you have to replace the boiler.

Hi
UNPLUG THE MACHINE
There is a reset button inside on the front side of the boiler (you have to take the top of the machine off. There are 4 screws and remove the water tank). It is located between 2 black wires and is a red button. Push it in and test. There is also an other problem that you might have. If the brew thermostat is bad it won’t heat. To test for this, push the steam switch and wait 15 seconds. Then open the steam knob and push the middle button and see if the water is warm. If it is then you need a new brew thermostat. That is the thermostat that has the red dot on the top. It sets on top of the boiler next to the steam thermostat. If you take the top off, make sure that the machine is unplugged.
If none of these things work check the heating element with an ohms meter. The reading in the terminals should be from 12 to 16 ohms. If no reading the elements is bad and you have to replace the boiler.

Hi

There is a reset button inside on the front side of the boiler (you have to take the top of the machine off. There are 4 screws and remove the water tank). It is located between 2 black wires and is a red button. Push it in and test. There is also an other problem that you might have. If the brew thermostat is bad it won’t heat. To test for this, push the steam switch and wait 15 seconds. Then open the steam knob and push the middle button and see if the water is warm. If it is then you need a new brew thermostat. That is the thermostat that has the red dot on the top. It sets on top of the boiler next to the steam thermostat. If you take the top off, make sure that the machine is unplugged.
If none of these things work check the heating element with an ohms meter. The reading in the terminals should be from 12 to 16 ohms. If no reading the elements is bad and you have to replace the boiler.

There is a reset button inside on the front side of the boiler (you have to take the top of the machine off. There are 4 screws and remove the water tank). It is located between 2 black wires and is a red button. Push it in and test. There is also an other problem that you might have. If the brew thermostat is bad it won’t heat. To test for this, push the steam switch and wait 15 seconds. Then open the steam knob and push the middle button and see if the water is warm. If it is then you need a new brew thermostat. That is the thermostat that has the red dot on the top. It sets on top of the boiler next to the steam thermostat. If you take the top off, make sure that the machine is unplugged.
If none of these things work check the heating element with an ohms meter. The reading in the terminals should be from 12 to 16 ohms. If no reading the elements is bad and you have to replace the boiler.