BOILERMATE SEEMS TO STICK AND STORED WATER DOES NOT HEAT UP?

Hello, great website, I wonder if you would be kind enough to help me?

We have a Boildermate 2000 which usually works just fine but sometimes I notice that the boiler is firing and the pump is running non stop. When I check the store water temperature it is very low and eventhough everything is firing and pumping it does not seem to get any hotter as if it has become stuck at a certain temperature.

Another problem is that both the store water pump and DHW pump are running even when there is no demand for hot water. Again it is as if they are stuck?

The only way to stop it is to switch the Boilermate of at the mains and switch it on again which has always solved the problem. I assumed that the pumps were getting stuck but if this was the case switching it off and on again would not fix it, which suggests that it is an electrical sensor problem. What worries me is if this happens when we are out or simply have not noticed the fault, and with energy prices as they are, we run the risk of ramping up some high bills!

Many thanks in advance for any help and advice!

Kind regards

James

You need to check that the unit is full.
Best way is to drain some out.
And make sure the top tank empties and fills up.
If not you have a blocked cold feed.
Above is the Golden rule for ALL thermal stores!
But it does sound like you have a PCB problem.
As you mention switching the unit off and on again does cure it for awhile.
Is your boiler on MAX ?
Mike
MGC/H2O
Norfolk

Cheers for the reply.

Some time ago I accidentally drilled through a hot water pipe and called a local plumber to come round and sort it out. It was very obvious that he did not understand the system any more than I did, so am worried that he did some damage. The other thing that I notice is that the store temperature never seems to get any higher that about 72 degreed which I know is low.

This may seem like a stupid question but how do you go about draining some safely without doing more damage.

The boiler is set on maximum.

I am getting an engineer round to look at it as we have Homecase which covers the heating system, but I am not very confident that he will be familiar with the system.


Cheers

To drain some out.
Get a hose and put on drain off inside unit.
Hose to out side or some where safe.
Open drain off, check water is draining out of hose.
Look in top tank (f&e)
See if the water starts to go down in the top tank.
If not stop, you have a blocked cold feed.
Also check that the ball valve is working.
Store temp will be around 76c.
So your temp of 72c is acceptable.
Try putting boiler pump speed on number 2 if on 3
Or on 3 if on 2.
Hard with out being in front of the unit.

I suspect a boiler fault here. The OP states the "boiler is firing and the pump is running non stop", but frankly, this cannot be the case. The boiler MUST be turning off sometimes or the thermal store would reach boiling point after a few hours of this and all hell would break loose.

Given the boilermate is at 72 degrees and not actually boiling, this tells us limited is energy being transferred from the boiler to the boilermate. This tells us the boiler cannot be running and alight non-stop although the OP perceives it to be. I think either the fan is running on the boiler 24/7 (meaning a boiler fault) or as Mike says, there is little or no circulation from the boiler up to the Boilermate and the boiler is actually cycling on and off correctly. Lack of circulation is caused by lack of water, a failed pump, a failure of the electricity supply to the pump or a closed water circuit.

What is the make and model of the gas boiler heating the Boilermate?

The thing is that the system seems to work fine 90% of the time, so surely there is sufficient water in the system.

This is exactly what I have observed....

When the store temperature drops to about 63 ish the boiler and pump kicks in and gradually re-heats the store to around 72. (I have watched the lcd display of this happening.) When reached the boiler switches off and the pump continues to run for at least 30 minutes or so (sometimes it does seem to over-run for longer though, is this normal?) before shutting off. All is well!

Sometimes however, we have luke warm water and the boiler has been firing for sometime, so I go and check the store temperature and it is at a low level of 57 ish. The thing is when this happens, I stand there watching the lcd display and the temperature does not budge, eventhough the boiler is firing and the pump is running very hot.

After leaving it for around an hour I decide that it is obviously not working and I do not want to waste energy, so I switch the Boilermate off at the mains, leave it for a minute or so, then switch it back on. After doing this everything starts working normally and the store temperature begins to increase almost straight away. Problem solved, but obviously I should not have to keep doing this.

I have assumed that this is an occasional pump failure, surely if there was depleted water in the store it would not work most of the time?

I know that the ball valve is working as I have pressed it.

The boiler is a Baxi, but am not sure of the model, as I am not at home at the moment.

As I said we have Homecare cover so I have made an appointment for an engineer to come round the week after next to give me a chance to monitor it before then. The problem is I have no confidence in them unless they are experts like you guys. Also at the time he checks it out, I am sure it will be fine.

Cheers guys for you help.

The pump over-running for 30 mins or more when the boiler has switched off is not right, and is an indicator of the problem. It tells us the boilermate is continuing to demand heat yet the boiler has chosen to turn itself off, probably because it is up to temperature. We now need to start with proper diagnosis, by checking for a 'call for heat' signal on the boiler SwL terminal. If there is a call for heat signal we know the boilermate is continuing to demand heat but not getting it.

This still suggests lack of circulationg water to me. Imagine the system is verrrrrryyyyy sloowwwwwwwly losing water, over months/years. How do you imagine it will behave at the point there is ONLY JUST enough water to work? Now take away a few CCs.... and a few more.... it will work intermittently as the pumps have almost enough water to pump, but just not quite enough.... they will prime themselves then air lock again, repeatedly and randomly. They will pump intermittently, quite possibly getting worse as the system temeprature rises. The hot water behaviour you describe supports this hypothesis :-)

I will always check on any thermal store.
That the unit has water.
And that means on draining some out does it take water from the top tank.
Lets say the tank hold 150 litres.
And it has only 100 litres.
You can heat it up and place a probe at the top of the unit.
You will obtain a temperature reading! Why?
Because any heat will rise and transfer upwards. And bearing in mind the unit internals are copper more so and very quick.
So that is why I have that "golden rule"
Experience has learnt me that.
Mike
MGC/H2O
Norfolk

Cheers for the help guys, I really appreciate it.

If I drain some and discover that I do have depleted water, what is the solution, ie how to I top it up?

Cheers

If the unit does not take water.
Then the cold feed is blocked.
You can try to clear it.
OR
Run a new pipe down from the f&e tank.
Alter the drain off on the unit so you can put the cold feed there and of course still a drain off too.
Or try filling the unit through the vent.
I would prefer trying to clear the blockage though.
But it can take time and a lot of effort.
Sludge remover can be a help.
But if in doubt get the professionals in !
Where are you in the UK ?
You can look on this site.
There are people who advertise.
Or Google up for some in your area.
Try typing Gledhill repairs in your town, city or county.
If not try Gledhill themselves who may recommend someone.
Mike
MGC/H2O
Norfolk