Diagnosing lack of hot water.

[dapaulio]

Looking for non it related advice

 

Reason I am posting this is in the hope that someone maybe able to help me understand my problem better because the to-Ing and fro-ing is beginning to get frustrating. (And my mrs is beginning to drive me up the wall with her constant complaints)

 

Thing is also I’m not sure how I can describe it so I’ll do my best and I will answer any follow up questions the best I can.

 

I live in private rented house where I have had numerous plumbers sent out by the agency done some tinkering and left saying fixed and it hasn’t. Now I’m not footing the bill here this is more an issue as it is affecting my living. I sure hope the landlord isn’t paying these clowns the agency is sending around???

 

I have a boiler (not combi) and a hot water tank that services hot water to radiators and the taps

 

The boiler is set to 80 degrees. The temperature is the only thing you can change.

The hot water tanks is upstairs in a cupboard and there does not seem to be a thermostat or anything you can alter other than the stopcock.

The pipes coming off the tank some are too hot to touch others you can hold comfortably or cold

 

My problem is my hot water to the tap doesn’t always deliver hot water. It can range from an acceptable to awful shower/bath. The water is never hot enough to the point where I have to use the cold tap mixer to cool it.

 

My shower has a mixer valve

My bath and taps are separate hot cold taps

 

The symptoms affect mainly upstairs taps (same floor as the hot water tank) more than down

 

The symptoms seem worse going in to the colder months

 

Regardless of whether we turn the heating on or not doesn’t seem to impact the lack of hot water to the tap.

 

Radiators when turned on fully open are red hot, you can’t touch for long with out hurting.

 

The cupboard with the hot water tank is always warm inside

 

Attached are photos of my boiler and tank for reference

I hope some one can help

Edited November 5, 2019 by dapaulio

[ZeroHour]

I have a similar setup as in a water tank and boiler to heat both the house and the tank.

My house has a controller where you can set a timer for heating and a timer for hot water as when the water tank is being heated the house doesnt necessarily get heated and vice versa.

Do have have any sort of thermostat or controller elsewhere?

It *sounds* like your water timing is off so its not heating the tank for when you need hot water. If we dont have the controller heat the water the tank will stay warm for a few hours but eventually it goes cold especially if used for a shower.

 

I am still learning the quirks of my system here as I am used to a combi in the past but we recently replaced the controller with tado to deal with heating and water.

[dapaulio]

I too am used to combi. This system confuses the hell out of me

 

Oh yeah forgot to mention that bit I do have a controller below the boiler which at present it set on manual override (always on) to heat the tank and off to heat the house. This controller only serves as a scheduler and on/off for water/heat

 

There is a thermostat also by the front door which controls the heating. But heating isn’t the problem and not turned on

 

For the purpose of testing I turned the heating off to prove to myself that it wasn’t consuming the hot water to the taps.

 

Unlike combi With this system I find I cannot heat the house unless the water is on also. Turning just the heating on eventually will go cold once all the hot water in the tank is I assume used...

 

The only positive I have found to this system is warm fluffy towels. Only slightly better when you have had a Luke warm shower

Edited November 5, 2019 by dapaulio

[Jobos]

You should have a thermostat on the cylinder aka tank and looking at the photo it could be the white box at bottom right behind the shelf.

 

Edit: there’s also a white box behind the valve towards the top but I would check the bottom box first.

Edited November 5, 2019 by Jobos

[Steve21]

What's it set to within the boiler controls? Unless I misunderstood what you said it sounds like you haven't actually changed the temperate setting for the water?

 

The boiler is set to 80 degrees. The temperature is the only thing you can change.

 

There's a panel just above that dial that should fold downwards isn't there? And there should be a few dials within the bottom panel on the front of the boiler with settings for water/heating temperate and then selecting what option you have set (Should normally look like a radiator and tap picture)

 

There should be a display inside that panel as well showing whats currently set, depending on the age of it (although from that picture it looks strangely like you have a wooden bar in front of the bottom panel? )

 

Steve

Edited November 6, 2019 by Steve21

[ChrisC]

I too am used to combi. This system confuses the hell out of me

 

Oh yeah forgot to mention that bit I do have a controller below the boiler which at present it set on manual override (always on) to heat the tank and off to heat the house. This controller only serves as a scheduler and on/off for water/heat

 

There is a thermostat also by the front door which controls the heating. But heating isn’t the problem and not turned on

 

For the purpose of testing I turned the heating off to prove to myself that it wasn’t consuming the hot water to the taps.

 

Unlike combi With this system I find I cannot heat the house unless the water is on also. Turning just the heating on eventually will go cold once all the hot water in the tank is I assume used...

 

The only positive I have found to this system is warm fluffy towels. Only slightly better when you have had a Luke warm shower

It doesn't *shouldn't* use the hot water in the tank to heat the radiators... The water heated in the boiler is pumped around the hot water loop and passes through a coil of pipe inside the tank and that heats the water in the tank that's then used for your hot water.

 

If the heating is on, a valve will just open to the heating loop instead (or as well).

 

As others have said, it sounds like a timing or thermostat issue.

 

I could be wrong, but looking at the shape it looks like an off peak electric heated style tank, is there an immersion heater in it? Or are there 4 pipes in it (one cold in, one hot water out and then there should be a feed and return for the actual heating loop pipe).

 

One thing to test is that one pair of the pipes should be hot to touch when the hot water is on, even if there is no demand.

[elsiegee40]

It’s a pressurised system isn’t it? That little expansion tank is the giveaway. It “should” give you hot water at the same pressure as your cold.

 

I am starting to wonder if you have a clogged valve or pipe somewhere

 

Although the most obvious question is whether the thermostat is actually working

Edited November 6, 2019 by elsiegee40

[elsiegee40]

Might help

[ChrisC]

It’s a pressurised system isn’t it? That little expansion tank is the giveaway. It “should” give you hot water at the same pressure as your cold.

 

I am starting to wonder if you have a clogged valve or pipe somewhere

 

Although the most obvious question is whether the thermostat is actually working

I wondered about a clogged valve, but (not following my own advice) discounted that with the fact they've had plumbers out and assumed competency in checking such things!

[jmak]

All the previous responses make sense to me (I have a similar system apart from the pressurised bit).

 

If the thermostat on the boiler is set to 80°, it will send water round the loop and run until the water coming back is at 80°. The water goes to a diverter valve (usually near the hot water tank) which sends water through the radiators, through a coil inside the hot water tank or both depending on whether you want heating, hot water, or both. As it flows round, it loses heat either via the radiators or to colder water in the hot water tank.

 

Your hot water tank #should# have an additional thermostat which should be set to 60° or less (water at 60° would cause serious injury), although older systems might not have. When I had our tank replaced 11 years ago it was mandatory, but the system when we moved in didn't have one.

 

The hottest pipe connected to your tank will be the "flow" (pipe coming from the boiler) and will be near the bottom of your tank.

 

The pipe nearest the top of the tank will be the hot water outlet. (The hot water rises through convection, so that when there's hot water left, but the boiler isn't running you should still get the hottest water in the tank.) If it never gets hot, either there's a thermostat on the tank that's set too low or it doesn't send a "call signal" to the boiler, or the rate of supply of heat via the "flow" is too low (i.e. hot water from the boiler is reaching the tank, but not enough to heat the volume of cold water in the tank. In that case, I'd start with the diverter valves. There might be a single valve, which is known as a midway diverter valve and they're notoriously unreliable (it's what I've got and I've replaced two in 11 years) or two separate valves. Either system performs the same function.

 

Assuming your outlet pipe is hot, you should then get hot water out of the bath tap - if it's a long way from the hot water tank, you might have to run it for a while, but it should get to a point where is almost as hot as the outlet pipe at the top of the tank.

 

If you're getting hot water, but the flow rate isn't high enough, it's probably the pressurisation system. The expansion tank in your photo should be at a about 1.5 to 2 bar when cold. They do need pressurising periodically but they can also fail.

 

Obviously if it's a rented property, it shouldn't be your problem to fix and you definitely shouldn't try, because you could then be liable/accused of breaking it... Hopefully one of the responses here gives you a bit more information to talk to your landlord or plumber about.

 

Good luck - no hot water is no fun in cold weather...

[dapaulio]

Thank you everyone for your responses to clarify I’m not looking to resolve. This is more of getting an understanding of what I have so I can go to the agency with a bit more knowledge. Honestly they could tell me anything and I would believe them.

 

Drawing of all the things in the tanks. There was an access panel where the pipes disappear and I found some chicken scratches which look to be letters which make more sense as annotated in the drawing

 

Supporting pictures

This isn’t attached to anything from the switch

 

What is this??? Is it dangerous because it looks to be

 

This is connected to the white box shown in the above picture which is clearly electric powering it and the two pumps below the tanks

Thanks again

Edited November 6, 2019 by dapaulio

[ChrisC]

The box attached to the cylinder looks to be the thermostat.

 

The dangerous looking one looks like the immersion heater. Which i'd guess was previously fed from the switch that's been "decomissioned" by terminating it in a junction box.

[dapaulio]

The box attached to the cylinder looks to be the thermostat.

 

The dangerous looking one looks like the immersion heater. Which i'd guess was previously fed from the switch that's been "decomissioned" by terminating it in a junction box.

 

Ok the white box attached the tank doesn’t seem to have any user functionality. There are screws to take the box apart but would I have to go to those sort of lengths to adjust the temperature?

[ChrisC]

Ok the white box attached the tank doesn’t seem to have any user functionality. There are screws to take the box apart but would I have to go to those sort of lengths to adjust the temperature?

They tend to have a dial to adjust.....unless the hot water temp is managed from a controller elsewhere!?

[dapaulio]

What's it set to within the boiler controls? Unless I misunderstood what you said it sounds like you haven't actually changed the temperate setting for the water?

 

 

 

There's a panel just above that dial that should fold downwards isn't there? And there should be a few dials within the bottom panel on the front of the boiler with settings for water/heating temperate and then selecting what option you have set (Should normally look like a radiator and tap picture)

 

There should be a display inside that panel as well showing whats currently set, depending on the age of it (although from that picture it looks strangely like you have a wooden bar in front of the bottom panel? )

 

Steve

 

No unfortunately with the boiler what you see is what you get. That panel is an access panel for boiler engineers allowing access to the boilers innards.

 

The bottom wooden panel is the cupboard the boiler is housed in

Thanks

[jmak]

I agree with Chris about the box on the tank being the thermostat for the hot water tank. Normally you can adjust without taking a cover off, but on mine you still need a screwdriver. People have a tendency to set them too hot, so it's probably just covered to dissuade users from fiddling. He's also right about the dangerous looking bit - it's the remains of an old immersion heater, but from the photos it doesn't look in a dangerous state. It's probably broken and they disconnected it rather than fix.

 

The other white box is essentially a junction box. Power goes into it and depending on the state of the programmer, hot water tank thermostat, room thermostat and boiler thermostat it will supply power to the boiler, the circulation pump (that's the red one in img_0867) and the diverter valve (the green thing with a black plastic box attached). I'd expect there to be some kind of lever or indicator on the black box - don't push our pull it, as it'll likely break, but you should see it move when you switch from off to heating on our got water on or both. That'd give you some idea of whether it's working.

 

The circulation pump is working, otherwise the radiators wouldn't get hot.

[dapaulio]

Update to the symptoms.

I don’t think I have done anything different other than have the hot water on 24 hours a day for a few days.

 

I had a shower this morning and the shower ran really hot for a minute. I thought brilliant hot shower then realised spoke too soon as it when Luke warm again for the remainder.

 

After asking my wife she said her shower did the same.

 

Now I don’t think it is the shower as we also have like warm baths and two we have had a new shower installed in the last few months which I wasn’t too pleased about as it seemed the new shower although identical replacement did no longer felt as powerful as the original. it was replaced due to a failing thermostatic valve. Which I’m now beginning to think that the shower wasn’t the original problem.

 

Can you see why I’m frustrated.

Opinions & advice welcome

Thanks again

[ChrisC]

Update to the symptoms.

I don’t think I have done anything different other than have the hot water on 24 hours a day for a few days.

 

I had a shower this morning and the shower ran really hot for a minute. I thought brilliant hot shower then realised spoke too soon as it when Luke warm again for the remainder.

 

After asking my wife she said her shower did the same.

 

Now I don’t think it is the shower as we also have like warm baths and two we have had a new shower installed in the last few months which I wasn’t too pleased about as it seemed the new shower although identical replacement did no longer felt as powerful as the original. it was replaced due to a failing thermostatic valve. Which I’m now beginning to think that the shower wasn’t the original problem.

 

Can you see why I’m frustrated.

Opinions & advice welcome

Thanks again

Pretty unlikely, but if it's going cold quickly there's a chance the tank is full of scale or sediment, meaning the volume of water available to heat is reduced, which means it runs out quicker....but I can't think the amount that can form would have such a dramatic affect..

 

Does it come out hot hot initially, or just "warm enough"?

[dapaulio]

Pretty unlikely, but if it's going cold quickly there's a chance the tank is full of scale or sediment, meaning the volume of water available to heat is reduced, which means it runs out quicker....but I can't think the amount that can form would have such a dramatic affect..

 

Does it come out hot hot initially, or just "warm enough"?

 

No it hot hot to begin with. Took me by surprise but within a minute of having hot hot water it began coming through as Luke warm

[dapaulio]

O I also removed the white box facia that was attached to the boiler and you were right, it is a thermostat. And it is set to 90 degrees

[ChrisC]

O I also removed the white box facia that was attached to the boiler and you were right, it is a thermostat. And it is set to 90 degrees

[ATTACH]55587[/ATTACH]

Ok, it should be ok to set your water to something like 65-70 degrees (safe temp to kill off nasties in the water as it's tank fed) otherwise it puts unnecessary demand on the boiler in terms of eco friendly-ness...

 

But also, if it's getting to that temp it would be far too hot to use for bathing without skin grafts!

 

Sounds like that's been done to compensate for an issue, and then if it's hotter, it can cause more scale to form more rapidly.

[ChrisC]

Ok, it should be ok to set your water to something like 65-70 degrees (safe temp to kill off nasties in the water as it's tank fed) otherwise it puts unnecessary demand on the boiler in terms of eco friendly-ness...

 

But also, if it's getting to that temp it would be far too hot to use for bathing without skin grafts!

 

Sounds like that's been done to compensate for an issue, and then if it's hotter, it can cause more scale to form more rapidly.

Actually just thinking, is it just the shower/bath affected, or is there a lack of hot water generally out of the sink taps in the bathroom and kitchen etc as well at the same time?

[3s-gtech]

I’m starting to think/agree that the hot water tank is knackered, especially as the rads are hot and some heat is getting into the hot water so the diverted valve is probably working. The fact that the immersion heater looks like it’s toast, the tank stat is set to ‘lethal’ and the issues you’re getting all point that way.

[BOOT]

Looks like a hybrid system - Combi boiler feeding a storage tank for power-shower. Could just be a stuck mixer valve, only letting mains cold water in and not water from the boiler. It'd still heat up on a timer via the boiler loop, just not get topped up. When shower etc is used, it'll only fill up with cold water.

[dapaulio]

Actually just thinking, is it just the shower/bath affected, or is there a lack of hot water generally out of the sink taps in the bathroom and kitchen etc as well at the same time?

 

Actually i think it all taps. It not really noticeable on any of the other taps as you don’t run off as much water as say the bath and the shower. But leaving taps open for a while starts hot then like the bath and shower loses its heat