Grant vortex outdoor combi 21 - HW not very hot

[nj53]

Previously we used to get decent HW. Now it's barely hot enough to run a bath. I've measured the temperature and it's a fairly constant 43degC. I believe factory setting is 50degC.

Boiler is firing ok and running continuously while hot tap is running. C/H is working fine. My other half thinks HW is better when C/H is on but I'm not convinced it's much different.

If I turn the TMV to Min, the water comes out cold. As I increase the setting it does get hotter but above 3.5 it makes no noticeable difference. (TMV is graduated Min 1 2 3 4 5 Max)

We have a private water supply which is not hard but it does contain minerals which produce some scale in kettle etc.

Is there anything I can do to diagnose the cause of the problem before calling out an engineer?

Thanks in advance.

 

[SimonG]

Check water pressure, check expansion vessel, check tmv for scale.

 

[nj53]

Thanks for the quick reply. Water pressure ok and expansion vessel replaced a few weeks ago.

I gently tapped the TMV and the water did get hotter for a while. It also came out brown suggesting that it probably is scaled up.

I think I'll call the engineer.

 

[Mattyt1987]

I know it was a long time ago but;

Did you find out what the problem was? Mines the same was all working fine a couple of months ago and now the water is hot for a couple of seconds and then gets Luke warm the longer I run it. Had the engineer out for a couple nof other problems I have had and he is charging through the roof. I'm in the wrong business I think! Used to come out hotter than the kettle but now can put hand under no problem.

thanks

 

[Millsy 82]

You need an oil engineer out there is a few things need checking out inside the boiler.

If your not happy with your current engineer why not post your location up on here and someone on here may be able to help you.

 

[nj53]

It turned out to be a faulty Hot Water Temperature Control PCB.

The boiler contains a small tank for the hot water called a heat store. There is a sensor (thermistor) on the heat store which is monitored by the PCB. If the temperature of the heat store falls then the PCB should fire the boiler to reheat the water. In our case this wasn't working and the water in the heat store was going cold or luke warm. Although the boiler still fired when a hot tap was run, it struggled to heat the water because the water in the heat store wasn't hot enough to start with.

Although your problem sounds similar it could be something else.

When you run a hot tap does the boiler fire and keep going while the tap is running?

 

[SimonG]

I know it was a long time ago but;

Did you find out what the problem was? Mines the same was all working fine a couple of months ago and now the water is hot for a couple of seconds and then gets Luke warm the longer I run it. Had the engineer out for a couple nof other problems I have had and he is charging through the roof. I'm in the wrong business I think! Used to come out hotter than the kettle but now can put hand under no problem.

thanks

What other problems have you had? And how much is through the roof?

 

[Mattyt1987]

Thanks everyone for the quick replies really appreciate it


Through the roof is;
already having him out for similar problem, once had him out as heating wasn't working which cost me £160 for an hours work, then had him out about 9-10 weeks ago because there was no hot water at all and that cost me £215 consisting of about a total of one hour and a halfs work, he will be having a decent Christmas by the sounds of it! Granted I don't know what parts he has fitted but the invoices haven't got a breakdown of what parts been fitted etc. just seems they can charge what they want as your stuffed without heating and don't seem to be that many oil engineers about.




Yeah the boiler fires and steam comes out so it's firing and working ok just seems to only have a bit of water in the tank. The taps downstairs seem to run through hotter and for a bit longer. I can't even run a bath hot enough to be enjoyable at the moment


in the ashby area, Just off m42

 

[nj53]

Yeah the boiler fires and steam comes out so it's firing and working ok just seems to only have a bit of water in the tank. The taps downstairs seem to run through hotter and for a bit longer. I can't even run a bath hot enough to be enjoyable at the moment

The following might help diagnose the fault.

1) Switch off both the C/H and H/W at the programmer
2) Run a hot tap until the water runs cold, then turn off the tap
3) Switch on the H/W at the programmer
4) The boiler should fire and run for several minutes to heat up the water in the heat store

If the boiler does not fire at step (4) then it's probably the PCB or sensor.

You may be able to get a hotter bath by opening the hot tap less and filling the bath slowly. You need to open the tap enough to cause the boiler to fire. Reducing the flow in this way may increase the water temperature.

 

[Millsy 82]

Go on oftec website and put your post code in I had a quick search off a postcode in your area and about 10 came up within a 10 mile radius and about another 15 in a 20 mile radius.

Don't touch it yourself as it may cost you more in wrongly diagnosed parts and you may touch something that you shouldn't and put your family and property in danger.

I appreciate that you may have paid a lot (I can't really comment on that as I don't know what he has done) but not everybody is out to rip people off and the vast majority of people want to make an honest living.

 

[SimonG]

I like to earn as much as possible. Thats why i work. When its cold my rates go up. Supply and demand.

 

[Mattyt1987]

I turned the heating off on the programmer then turned the switch on the boiler off and ran water until it was cold. When I switched it back on it didn't fire. The boiler didn't fire until I ran the hot tap. Is this not right. Thanks again everyone for the replys.

i'm not saying you rip everyone off Simon just a but of banter. Are you on here to help or try and get an argument out of somebody. I'm a tradesman myself and understand you have to make money just like stuff to get sorted for as less money as possible. I appreciate your wolf of Wall Street business speech though.

 

[SimonG]

I turned the heating off on the programmer then turned the switch on the boiler off and ran water until it was cold. When I switched it back on it didn't fire. The boiler didn't fire until I ran the hot tap. Is this not right. Thanks again everyone for the replys.

i'm not saying you rip everyone off Simon just a but of banter. Are you on here to help or try and get an argument out of somebody. I'm a tradesman myself and understand you have to make money just like stuff to get sorted for as less money as possible. I appreciate your wolf of Wall Street business speech though.

Normally on a post like this you would have had half a dozen replies giving ideas/fixes by now. Looks like your banter has done a Jimmy Bullard and as a tradesman you should know better than rubbing the people you want help from the wrong way.

Wolf of wall street, never seen it. Any good?

So is it general builder or decorator?

 

[nj53]

I turned the heating off on the programmer then turned the switch on the boiler off and ran water until it was cold. When I switched it back on it didn't fire. The boiler didn't fire until I ran the hot tap. Is this not right.

No, it is not right. As soon as you switched the boiler back on it should have fired, and ran for several minutes, to reheat the cold water in the heat store.

I suspect it's either a faulty Temperature Control PCB or the sensor. More likely the PCB because there's more to go wrong with that.

One thing we noticed when we had this fault was that the water was hotter if the central heating had just been on. You could try turning up the room thermostat for 15 minutes before running the bath.

 

[Mattyt1987]

Cheers nj53 I thought I had done a "jimmy bullard" then �� phew!!
as i said before appreciate your reply and help on this issue. The water does se to run through slightly hotter when the heating is on. I'll have to get an engineer out again. I'll have a whole new boiler soon with all these parts getting fitted. Then again I wouldn't know because I'm a painter & general builder apparently.

 

[nj53]

The PCB was about £50 and it took about 10 mins to replace.

Ever since the boiler was installed 7 years ago, we've had at least one or two faults per year. It has been the most unreliable boiler we've had.

Luckily though we've got a great engineer.