Water Heater Draining and Descale

[Luke675]

Hello, I've recently moved into a house here in Sweden, my electric hot water system is starting to make a hissing noise. I'm thinking maintenance on this thing has not been done for a while and hopefully could just need a descale.
Obviously first thing would be to drain the system of water and pressure. Although after isolating water and power the usual process does not seem to be working?
I have a hot water tap open in the house to allow air intake, there is no brand name on this thing but it doesn't look too old, also all connections are to the underside of the tank, cold water in, hot water out....any suggestions???

 

[WorthFlorida]

The hissing is the water right at the hearing elements when power is on. It is similar when a pot of water is being heated to a boil, at some point of heating, usually just before boil, you’ll hear a similar hiss sound.
The elements have a coating of minerals that can be removed and soaked in vinegar. May just be easier to replace them since a vinegar soak will not remove 100% of the minerals and the element itself could be eroded some.
Electric water heaters do not experience mineral settlement at the bottom of the tank as does natural gas or propane fired water heaters. Doing a drain and flush most likely will not improve anything but it shouldn’t cause a problem.
You didn’t state it, is it a wall mount water heater or tankless? If it is a tankless system there is little or no water storage tank. You cannot always tell the age of the unit by the exterior cover. A picture would help and call on a local plumbing house or supplier to see if anyone knows of the brand. Then you can get a user manual for any descaling procedure.

 

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[Luke675]

The hissing is the water right at the hearing elements when power is on. It is similar when a pot of water is being heated to a boil, at some point of heating, usually just before boil, you’ll hear a similar hiss sound.
The elements have a coating of minerals that can be removed and soaked in vinegar. May just be easier to replace them since a vinegar soak will not remove 100% of the minerals and the element itself could be eroded some.
Electric water heaters do not experience mineral settlement at the bottom of the tank as does natural gas or propane fired water heaters. Doing a drain and flush most likely will not improve anything but it shouldn’t cause a problem.
You didn’t state it, is it a wall mount water heater or tankless? If it is a tankless system there is little or no water storage tank. You cannot always tell the age of the unit by the exterior cover. A picture would help and call on a local plumbing house or supplier to see if anyone knows of the brand. Then you can get a user manual for any descaling procedure.

Cheers for the reply. It's a wall mount. I was thinking of the descale with vinegar once it was empty of water and pressure. There is like a sump bolt top and bottom where i could use for a filling and drain point, i don't want to go near them though until pressure is released.

 

[WorthFlorida]

First, be sure power is turned off. Are sure it is not a tankless system? Before you do it know where you can immediately get replacement heating elements. The acid in the vinegar could eat away any soft spots on the elements thus causing a tripped breaker and no hot water. If you have the tools replacing the heating elements is a sure fix but some hissing will occur but usually very low and short duration. I also do not know how the anode rod will react to the acidic vinegar?

I just tried a vinegar soak in my Keurig coffee maker and it barely made a difference to its heating the water right after a brew. It hisses to a growl.

If you know the age of the heater you maybe better off replacing it. It’s the same here in the USA. It seems most try to get every last bit of life out of water heaters, air conditioners, furnaces and car batteries. However, it is your budget and like most and myself, after a house closing usually not much money is left in the bank.

 

[DIYorBust]

I've found I've generally had a better experience using citric acid for descaling, but I'm sure someone will have a vinegar argument. Also you could try rubbing with a lemon after soaking.

I think trying to get more life out of these appliances may be a function of labor costs in the area. The appliance itself is probably not that expensive, but the headache and cost of getting someone in there to install it can make you want to squeeze a few more years out. Often you can DIY the maintenance but not the replacement.

 

[Luke675]

Thank you gents, you've been most helpful, with that said emptying the tank is not working for me as it has done in the past?