US-Style Water Heater: Tips for Optimal Performance and Safety in the UK

[Guineafowl]

Hi all,

I've just moved to a house in the Highlands whose previous owner was American, and insisted on installing US appliances, presumably shipped over at great expense. I wonder if our US friends on here could help with the water heater:

Is it just California state law to write all that guff all over it, or is it everwhere? UK heaters have hardly anything written on them.

Anyway, it has a two-heater arrangement that I'm not familiar with. The upper heater seems bigger, and has some kind of switchover so that only one heater can be activated at a time. In the UK, the suggested temp is at least 55 or 60 degC to prevent Legionnaire's disease. In any case, it doesn't output enough hot water, so I want to turn it up - do I set the lower to 60 and the upper slightly higher, or will that just permanently deactivate the lower heater?

Any help greatly appreciated.

 

[.Scott]

Is it just California state law to write all that guff all over it, or is it everwhere? UK heaters have hardly anything written on them.

I don't know how much of it is law, but it is certainly the practice everywhere in the US.

Anyway, it has a two-heater arrangement that I'm not familiar with. The upper heater seems bigger, and has some kind of switchover so that only one heater can be activated at a time. In the UK, the suggested temp is at least 55 or 60 degC to prevent Legionnaire's disease. In any case, it doesn't output enough hot water, so I want to turn it up - do I set the lower to 60 and the upper slightly higher, or will that just permanently deactivate the lower heater?

Any help greatly appreciated.

Here is a link that describes the basic operation:
http://www.whirlpoolwaterheaters.co...ter-heaters-work/standard-electric-operation/
Set both thermostats to the same temperature. If any thing, set the upper one slightly higher.
The purpose of two thermostats is to work on the water you will use next to the correct temperature. Then with that reserve available for immediate use, the remaining water is heated by the lower element.

Looks a lot like this one:

 

[Averagesupernova]

The reason the top element looks bigger is because the thermostat itself is larger. The heating element itself is not larger. The thermostat is larger because it is responsible for switching off the lower thermostat when the top thermostat calls for heat. Only one element ever runs at a time.

 

[Guineafowl]

Thanks to you both. I've set them both to about 60 degC, with the upper slightly higher as suggested.

It's always interesting how regs differ across the pond - in the US, it's a 52 C max to prevent scalding; in the UK, it's 60 C min to prevent Legionella.

 

[anorlunda]

Thanks to you both. I've set them both to about 60 degC, with the upper slightly higher as suggested.

It's always interesting how regs differ across the pond - in the US, it's a 52 C max to prevent scalding; in the UK, it's 60 C min to prevent Legionella.

Yes indeed. One can almost visualize the human dynamics in those standard setting committee meetings. Accidents of history and backward compatibility also play a large role.

If engineers ruled the world, we would sort hazard priorities in strict order of calculated risk. The public would hate us.[emoji2]

 

[krater]

Maaaan those are two pictures of some wickedly ugly installs...anyway in OP from what I can make out of the markings on the sticker omlette your water heater seems to base the energy guide ratings on around 0.10 dollars/kwh. Putting the age of the water heater at maybe early 2000s, or sooner, unless I miss my guess? Worth a look at replacing someday as I've seen standards on insulation ect come a long way since then in NA products.

 

[Guineafowl]

Maaaan those are two pictures of some wickedly ugly installs...anyway in OP from what I can make out of the markings on the sticker omlette your water heater seems to base the energy guide ratings on around 0.10 dollars/kwh. Putting the age of the water heater at maybe early 2000s, or sooner, unless I miss my guess? Worth a look at replacing someday as I've seen standards on insulation ect come a long way since then in NA products.

Yes, some kind individual has boxed in the tank so I can't get it out without cutting the pipes in front. Also, it's odd that the tank has no provision for an indirect coil to heat it with the oil-fired range cooker (Rayburn) that runs the radiators.

You could be right about the age. It's all going to be torn out soon anyway, as the entire heating setup is being replaced with a wood chip boiler system.

The wiring is also interesting - circa 1960 vintage, with individual L and N conductors sheathed in a sort of sticky fibrous material and rubber. Run through steel conduit:

Sockets without earthing: about 40%.
Sockets joined to a lighting circuit: 30%. Solution to blowing fuse? Fuse wire doubled over.
1 length of conduit quietly hums to itself.
Insulation resistance test result @500V: 300 kohm (L+N to E). Min value: 1 Mohm. Expected value: 100s of Mohm.

Conclusion A: Someone was 'keen' on do-it-yourself wiring.
Conclusion B: Some new wiring needed.

 

[I like Serena]

It's all going to be torn out soon anyway, as the entire heating setup is being replaced with a wood chip boiler system.

As an alternative, have you considered not replacing the boiler at all?
Advantages: saves a lot of space, saves on equipment that does not have to be maintained, saves a bit on leaking heat, and saves money.
Disadvantages: it takes slightly longer to get hot water, and the system will stop heating your house while you're using hot water.

This is what I did recently when my boiler was leaking, and getting way too hot.
At the same time I replaced the heater by a newer model that is more efficient, significantly smaller, and able to both heat the house and supply hot water.
Now I have an amazing amount of space, and everything looks much simpler and neater.

 

[Guineafowl]

As an alternative, have you considered not replacing the boiler at all?
Advantages: saves a lot of space, saves on equipment that does not have to be maintained, saves a bit on leaking heat, and saves money.
Disadvantages: it takes slightly longer to get hot water, and the system will stop heating your house while you're using hot water.

This is what I did recently when my boiler was leaking, and getting way too hot.
At the same time I replaced the heater by a newer model that is more efficient, significantly smaller, and able to both heat the house and supply hot water.
Now I have an amazing amount of space, and everything looks much simpler and neater.

Is that a tankless combi boiler? Not a bad idea, but the wood chip boiler is being installed to heat the main house. I live in an annexe of this, so will benefit from free heat.

To give you an idea, the proposed wood chip system is 202 kW.

 

[I like Serena]

Is that a tankless combi boiler? Not a bad idea, but the wood chip boiler is being installed to heat the main house. I live in an annexe of this, so will benefit from free heat.

To give you an idea, the proposed wood chip system is 202 kW.

I'm a bit unclear on the proper words. In my country what we call a 'boiler' is a big tank that typically gets heated by a separate heating system. That's the big tank that you've shown in your picture. The heating system usually has 2 functions: to heat water for the pipes that are heating the house, and to heat the water for the boiler, which is used in turn to tap hot water in the house.
So what I'm talking about is a tankless heater (although it probably has a very small tank inside to heat the water). Do you still call that a boiler?

When I get home, I'll take a look at the specifications of the system.

 

[Guineafowl]

I'm a bit unclear on the proper words. In my country what we call a 'boiler' is a big tank that gets heated by a separate heating system. That's the big tank that you've shown in your picture. That heating system usually has 2 functions: to heat water for the pipes that are heating the house, and to heat the water for the boiler, which is used in turn to tap hot water in the house.
So what I'm talking about is a tankless heater (although it probably as a very small tank inside to heat the water). Do you still call that a boiler?

When I get home, I'll take a look at the specifications of the system.

The tank in the picture is just called a hot water tank, heated by electric immersion heaters. The separate thing that heats the water in other systems is a boiler.

The tankless thing you describe is a boiler, yes.

 

[CWatters]

Guineafowl... The system you have isn't totally unusual in the UK. We had one in the 1980s. The two elements and stats allow you to hear more/less hot water. The hot water rises to the top heating the tank from the top down. So if just the top element and stats are used it will only heat down to that stat. If the lower heating element and stats are used the tank heats down to that level so there is more hot water in the tank. The hot water should be drawn off the top of the tank and new cold water is injected at the bottom.

The main disadvantage is the cost of electricity compared to oil or gas or an air sourced heat pump.

 

[CWatters]

See the column "pence per kWh after boiler efficiency"..

http://www.nottenergy.com/energy_cost_comparison

Although I don't think this takes into account E7 rates.

 

[Guineafowl]

Guineafowl... The system you have isn't totally unusual in the UK. We had one in the 1980s. The two elements and stats allow you to hear more/less hot water. The hot water rises to the top heating the tank from the top down. So if just the top element and stats are used it will only heat down to that stat. If the lower heating element and stats are used the tank heats down to that level so there is more hot water in the tank. The hot water should be drawn off the top of the tank and new cold water is injected at the bottom.

The main disadvantage is the cost of electricity compared to oil or gas or an air sourced heat pump.

Thanks. The reason I'm fiddling is that there wasn't enough hot water for the wife to have a bath and me to have a shower at the same time. The water went cold halfway through. From what you and others say, the top heater is dominant, and will only allow power to the lower when its stat goes off. The tank was originally set to favour the upper, with the lower kicking in only when things got really cold. The problem was sorted by setting the upper to 62 and the lower to 60 degC (or thereabouts).

I have no idea why a proper indirect tank was not installed to take advantage of the oil-fired range boiler. Immersion heaters are a summer backup at best, and power cuts are common in Highland winters.

 

[sophia35]

Hi all,

I've just moved to a house in the Highlands whose previous owner was American, and insisted on installing US appliances, presumably shipped over at great expense. I wonder if our US friends on here could help with the water heater:

View attachment 209302

Is it just California state law to write all that guff all over it, or is it everwhere? UK heaters have hardly anything written on them.

Anyway, it has a two-heater arrangement that I'm not familiar with. The upper heater seems bigger, and has some kind of switchover so that only one heater can be activated at a time. In the UK, the suggested temp is at least 55 or 60 degC to prevent Legionnaire's disease. In any case, it doesn't output enough hot water, so I want to turn it up - do I set the lower to 60 and the upper slightly higher, or will that just permanently deactivate the lower heater?

Any help greatly appreciated.

Tankless water heaters are more convenient and high performance than traditional water heaters. Tankless requires a very small space to set up and they consume low power. I use a 6L tankless water heater inside my house.

 

[dlgoff]

Tankless water heaters are more convenient and high performance than traditional water heaters. Tankless requires a very small space to set up and they consume low power. I use a 6L tankless water heater inside my house.

You do realize that this thread is almost 2 years old. However, I agree that a tankless water heater might have been a good choice for the OP.

 

[Guineafowl]

This system has been turfed out in favour of the woodchip boiler now. I guess the only power source generous enough to run a tankless system would be gas, and there is no mains gas here. LPG tank next best thing, I suppose.

 

[sophia35]

Tankless water heaters are more convenient and high performance than traditional water heaters. Tankless requires a very small space to set up and they consume low power. I use a 6L tankless water heater inside my house.

You do realize that this thread is almost 2 years old. However, I agree that a tankless water heater might have been a good choice for the OP.

This system has been turfed out in favour of the woodchip boiler now. I guess the only power source generous enough to run a tankless system would be gas, and there is no mains gas here. LPG tank next best thing, I suppose.

Nowadays, most people prefer to use a tankless water heater instead of the old tank. Tankless is more convenient, easy to operate, needs less power, and small space to install.
[probable spam deleted]

 

[russ_watters]

Hi all,

I've just moved to a house in the Highlands whose previous owner was American, and insisted on installing US appliances, presumably shipped over at great expense. I wonder if our US friends on here could help with the water heater:

View attachment 209302

Is it just California state law to write all that guff all over it, or is it everwhere? UK heaters have hardly anything written on them.

Some is required by US law, some is by choice by the manufacturer hoping not to get sued.

Anyway, it has a two-heater arrangement that I'm not familiar with. The upper heater seems bigger, and has some kind of switchover so that only one heater can be activated at a time. In the UK, the suggested temp is at least 55 or 60 degC to prevent Legionnaire's disease. In any case, it doesn't output enough hot water, so I want to turn it up - do I set the lower to 60 and the upper slightly higher, or will that just permanently deactivate the lower heater?

There should only be one thermostat.

You can almost certainly find the manual online.

Edit: D'oh; necro'd

 

[russ_watters]

Tankless water heaters are more convenient and high performance than traditional water heaters. Tankless requires a very small space to set up and they consume low power.

Everything is true except for the last part: the major drawback of tankless water heaters is they require much higher power than tanked water heaters. The entire point of the tank is to reduce the power requirement.

 

[Guineafowl]

Everything is true except for the last part: the major drawback of tankless water heaters is they require much higher power than tanked water heaters. The entire point of the tank is to reduce the power requirement.

Power is to energy as speed is to...

 

[russ_watters]

Power is to energy as speed is to...

If your point is that Sophia said power but meant energy, that was a very unfortunate error.

 

[Averagesupernova]

Just try running a tankless water heater on the same breaker that ran that old fashioned tank water heater and see how far you get.