Oil fired Central Heating thermostat may not be working.

anotherquestion

Just an update on this, I have since found out today, that though the old boiler replacement grant scheme ended where I live, there is actually another one in place which may benefit me, but I would have to wait until April to apply.

So forgive me for asking one last question on this, as I am sure some of your guys are probably fed up with all the posts I have posted on the thread.

Does the thermostat have to be specific to the old 35 cast iron oil boiler I have, or is it possible to add another make of thermostat that should do the job and tie me over until April when I will apply for grant.

As stated boiler is running fine, but just won't switch off unless I do it manually at power point timer.

I will probably have to get a heating guy to look at this.

Sorry again for all the posts as some of you may feel I am neither coming or going with this issue.

:}

Section62

anotherquestion said:

Does the thermostat have to be specific to the old 35 cast iron oil boiler I have, or is it possible to add another make of thermostat that should do the job and tie me over until April when I will apply for grant.

It isn't clear the fault is with the boiler thermostat - there are other things in the system which could be faulty, which is why a couple of us have suggested getting a second opinion from someone else.

If it is the thermostat then it is possible it is a generic one and a competent heating engineer could sorce a suitable replacement.  Because the make/model isn't particularly common it may be harder to get a genuine/specific part if the manufacturer made their own.

anotherquestion

Thanks for all the help, all up and running again with the old cast iron oil boiler, an electrician fitted  new thermostat, did the trick, boiler is switching itself off when temperature is reached.

Heating/plumber had a look to diagnose the problem, said that it was in fact dangerous as boiler not switching off could mean that once the water reached a temperature of 100 degrees could lead to the boiler actually exploding.

I have filled in a grant application for a new boiler as 35-36 years with old cast iron one is not bad going.

Once again many thanks for all replies.





 

Section62

anotherquestion said:

Thanks for all the help, all up and running again with the old cast iron oil boiler, an electrician fitted  new thermostat, did the trick, boiler is switching itself off when temperature is reached.

Good news!  The odds were it was a simple fault that someone who knew what they were doing would be able to fix - using a generic part if necessary.

Heating/plumber had a look to diagnose the problem, said that it was in fact dangerous as boiler not switching off could mean that once the water reached a temperature of 100 degrees could lead to the boiler actually exploding.

I'd say the so-called heating enginer/plumber is the dangerous thing here.  As I said earlier in the thread, the boiler should have a safety 'limit stat' in addition to the one controlling the temperature of the circulating water (aka system or flow temperature).  This would shut the boiler down before there was a risk of boiling - if there is no limit stat, or this one had failed, then the boiler would be unsafe to operate.  The system should also either be 'open vented', or else should have a pressure relief system.  In either case an excessive pressure shouldn't happen - the boiler cannot "explode" unless the system it has been installed in is unsafe.

I have filled in a grant application for a new boiler as 35-36 years with old cast iron one is not bad going.

Now the thermostat has been fixed you should get several more years of service from the boiler, you don't need to change it just because it is 35 years old... and there is possiblity this one could keep on working longer than one you buy now to replace it.

Obviously if you can get a generous grant to replace it then consider that option, but if replacing the boiler is going to cost you money you can't afford then get some other opinions, rather than relying on what this engineer/plumber has told you.

ThisIsWeird

Yes, if oil boilers exploded just because two wee thermostats failed, there would be regular 'bangs' across the countryside.
But, you also don't want to be in the position of the boiler literally boiling - well scary.
AnotherQ, did your sparky also test the overheat 'stat whilst there? If not, that's a shame.
Both these 'stats are usually very obviously positioned, especially on old boilers.
The control 'stat in our ol' Island home's ancient oil boiler failed a few years back, and the part was 'obsolete'. I looked up the spec of the original - especially the dimensions of the vial - and found a more recent equivalent very easily. Fitted and working as it should.

anotherquestion

Thanks, well electrician was here for quite a while, waited to such times as the water reached the correct temperature and boiler switched itself off. I have also kept an eye on it over these last number of days to make sure that it really does switch itself off.

I wasn't ever aware there is an overheat stat until you mentioned it, so not sure if he tested that or not, was really reasonable as regards charge too.

ThisIsWeird

Just for reassurance, if both stats fail, you'll get plenty of warning - sizzling, gurgling, banging, water being ejected out safety pipes. But no ultimate 'bang'.