Stanley Range boiler: water boiling

FrostyKK

Hello - new here.

We have a 1987 Stanley oil fired 90 which we have minded carefully over the years. Its had about 4 sets of baffles; a new burner; new oil pump, solenoids etc. It has kept going and is now part of the family (its also so integrated in the kitchen that extracting it is going to be a huge problem!!).

The problem is that the water seems to seriously boil (gurgling) at lower and lower thermostat and water temperatures. At this point, we have the boiler stat set at about 55 deg C and it still gurgles worryingly. Has anybody got any ideas? Baffles seem fine. The plumbing has not changed. It has a pump controlled by a pipe stat which turns on as it should. There are two boilers on the system; the Stanley and a back boiler; each with their own pumps and one valves etc.

Any ideas would be appreciated as we would like to keep it working away.

Thanks in advance.

fully floating

If this has not always been an issue with the cooker there are to possible problems that should be easy enough to check

1) check the setting of the pipe stat has not been changed
2) try lowering the temperature on the cooker thermostat till it stops boiling, it might be starting to fail and is losing calibration

FrostyKK

Thanks fully floating,
The pipe stat (now buried in the wall!) seems to be fine as it switches the pump on very quickly as it always has.
Yes I have lowered the temperature but I think the water going to the rads is cooler than it used to be if we have the stat low enough to stop the boiling. Having said that, it is the older model with the stats on the top right corner where I think the capillary routing may have caused problems earlier? But if all of the water was boiling, would not the high limit trip switch have tripped out? Can boilers develop an internal circulation problem where parts are boiling but not near the stats?

I think we must have one of the oldest oil fired 90s still running. What normally causes them to fail. Does the boiler leak? Will the boiling cause problems? I would like to keep the Stanley if we can, so any help appreciated.

Thanks again for the help

Dtp1979

If the stat is reading ok then it's eaither a dodgy circulating pump or a buildup of sludge in the Boiler. Either Is very likely tbh

FrostyKK

Thanks DTP,
The pump is whirring away merrily (grundfoss ups 15-45) on 3rd speed without any odd noises and seems to get the water around to the rads quickly. If it was dodgy, would the boiler stat simply not protect it from boiling though even if the pump was dodgy?

However a build up of sludge may indeed match the symptoms. Is this common and what causes it? We have had no leaks and when the system was drained to add a rad a year or two ago, a corrosion inhibitor was added.

I dread the answer, but what can be done if there is a build up of sludge?

Regards

FrostyKK

While i cannot see the post here, I got an email from Boards re Jim F asking are both pumps working.

Well both pumps can work together. The adjustable pipe stat for the back boiler is located in the hot press along with both pumps so if both stats call for the pumps, they are both turned on. There are one way valves. Fitted to stop each pump circulating in the boiler of the other when only one pump is on ( i think !).

Dtp1979

FrostyKK wrote: »

Thanks DTP,
The pump is whirring away merrily (grundfoss ups 15-45) on 3rd speed without any odd noises and seems to get the water around to the rads quickly. If it was dodgy, would the boiler stat simply not protect it from boiling though even if the pump was dodgy?

However a build up of sludge may indeed match the symptoms. Is this common and what causes it? We have had no leaks and when the system was drained to add a rad a year or two ago, a corrosion inhibitor was added.

I dread the answer, but what can be done if there is a build up of sludge?

Regards

Adding inhibitor to an already corroded system would probably do more harm than good. Incorrectly piped dual systems create a lot of sludge. Systems with leaks also are big culprits. Get someone out who understands heating systems and also does powerflushing. More than likely a powerflush will fix it

jimf

FrostyKK wrote: »

While i cannot see the post here, I got an email from Boards re Jim F asking are both pumps working.

Well both pumps can work together. The adjustable pipe stat for the back boiler is located in the hot press along with both pumps so if both stats call for the pumps, they are both turned on. There are one way valves. Fitted to stop each pump circulating in the boiler of the other when only one pump is on ( i think !).

cant figure out where that post went

I was wondering if you had a faulty nr valve would the 2 pumps be circulating against each other I don't know if it would make a difference

not really into the plumbing side of things myself more servicing and breakdowns etc

maybe dtp might give his opinion

TPM

if the oil cooker is boiling the water when the back boiler is not lighting you have to have a problem with the temperature control of the oil cooker(possibly other issues also)

some of the stanley cookers have 2 stats(not including the pipe stat) one for heating(water) and one for cooking.
when the heating one is on it turns off the burner when the water reaches the set temperature set point, if this is not happening

the stat could be faulty and not switching off

the heat isnt reaching the stat could be caused by air or gunk in the boiler, or the bulb pulled out of its pocket

or the cooker stat could be keeping the burner running and causing the water to heat past the heating stat set point.

I have had a few of these that the heating stat failed on, started by intermittent over heating then to continuously doing it

FrostyKK

Thanks all for replies.
Firstly the power flush sounds interesting although we never had leaks, i just mentioned adding the corrosion inhibitor following a drain down to replace a rad with a larger one.

While we have a two stat system with single burner, i don't think thats the problem as it occurs with baffle set to boiler and cooker stat to max. Also while the water is boiling, the heat of the water going to the rads is not that high. I think it is possibly poor circulation within the boiler (sludge)???

How can you do a power flush of a pretty permanently installed cooker with all pipes behind plaster? I presume you could not flush from the hot press draining connections as putting all joints under a high pressure may not be wise??

jimf

I wonder would the circulating pump not be man enough anymore for the job

it just may not be able to get the water away from the cooker fast enough

dtp has mentioned this above already

Dtp1979

FrostyKK wrote: »

Thanks all for replies.
Firstly the power flush sounds interesting although we never had leaks, i just mentioned adding the corrosion inhibitor following a drain down to replace a rad with a larger one.

While we have a two stat system with single burner, i don't think thats the problem as it occurs with baffle set to boiler and cooker stat to max. Also while the water is boiling, the heat of the water going to the rads is not that high. I think it is possibly poor circulation within the boiler (sludge)???

How can you do a power flush of a pretty permanently installed cooker with all pipes behind plaster? I presume you could not flush from the hot press draining connections as putting all joints under a high pressure may not be wise??

Yes it's don't me from the hotpress. It's not high pressure either.