Sewage Pumps Archives - Mawdsleys Pump Services

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8 Common Problems with Sewage Pumps and How to Fix Them

Sewage pumps are critical to wastewater management in almost every type of premises — from private homes to large commercial and industrial sites. When they develop a fault, the consequences range from inconvenient to seriously disruptive: backed-up toilets, overflow risk and costly downtime.

This guide covers the 8 most common sewage pump problems, what typically causes them, and what you should do — including when the situation calls for professional sewage pump repair, a maintenance visit or a review of your current servicing arrangement.

If you need urgent help, call our team now on 0117 954 8030. We operate 24/7, 365 days a year.

1. The Sewage Pump Won’t Start

A sewage pump that fails to start is one of the most common call-outs we attend. Causes include:

Power supply failure or tripped circuit breaker
Faulty control panel or sensor
Motor failure
Debris or a blockage jamming the impeller
Pump seized after a prolonged period without use

What to do: Check the power supply and control panel first. If there’s no obvious electrical fault, do not attempt to free a jammed impeller manually — contact a pump engineer. An experienced technician will carry out a full diagnostic inspection and carry out the sewage pump repair on-site where possible, or arrange a swap-out to minimise downtime.

2. The Sewage Pump Won’t Turn Off

A pump running continuously is often caused by a stuck or failed float switch, or a blockage preventing the water level from dropping. A tell-tale sign is an unexplained spike in electricity bills.

Running a sewage pump dry — without water to cool the motor — will damage the seals and ultimately destroy the pump entirely.

What to do: If the pump is non-critical, isolate it by cutting the power. Then arrange an inspection with an engineer as soon as possible. Float switch replacement is a straightforward sewage pump repair, but left unattended, the fault will cause far more expensive damage.

3. Toilets Are Backing Up

Toilet backups linked to a sewage pump are usually caused by a blockage within the pump, a fault at the sewage treatment plant, or a septic tank that needs emptying.

What to do: Stop using toilets, taps and drains immediately — every flush adds more wastewater to an already overloaded system. Contact a pump engineer urgently. This is not a fault that resolves itself, and continued use will escalate the problem quickly.

4. Leaking from the Pump or Pipework

Leaks are typically caused by cracked pipework, a failed non-return valve, or a perished seal. A failed non-return valve allows sewage to recirculate back into the sump — the pump then has to work harder to keep up, increasing both energy consumption and wear.

What to do: Carry out a visual inspection to locate the source of the leak. If you can identify the failing component, you may be able to order a replacement part and describe the fault clearly when you call. If you cannot identify the leak, contact a pump engineer immediately.

⚠️ Leaks from a sewage pump are a serious emergency. Raw sewage leakage poses a health risk and can cause significant structural damage. Call us now on 0117 954 8030 for fast 24/7 support.

Regular sewage pump maintenance will catch seal and valve deterioration before it becomes a leak — this is one of the most common faults our engineers identify during scheduled service visits.

5. The High-Level Alarm Is Sounding

High-level alarms are designed to trigger when water in the pump chamber rises to a critical level — usually because the pump has failed or is running below capacity.

What to do: Do not silence the alarm and carry on. Switch off the pump, stop using water on the premises, and contact an engineer for emergency assistance. Ignoring a high-level alarm risks sewage overflow.

6. Loud Noises from the Pump (Vibrations, Banging)

Unusual sounds are often caused by loose or improperly secured pipes vibrating under pressure, a malfunctioning check valve causing water hammer, or an impeller that has come loose within the pump casing.

What to do: Carry out a visual check of the pipework fixings and pump housing. If the noise is coming from inside the pump body, do not attempt to access it — arrange an inspection with an engineer who can assess the impeller and valve and carry out the appropriate sewage pump repair.

7. Pump Burnout

Burnout is one of the most costly outcomes of a neglected sewage pump system. Common causes include:

Using the wrong pump for the application (wrong flow rate or head pressure)
Heavy usage surges exceeding the pump’s capacity
A failed float switch causing the pump to run dry
Incorrect overload settings on the control panel
A partial blockage making the motor draw excessive current

What to do: If you have experienced burnout, the pump will need to be replaced or fully overhauled. More importantly, the root cause needs to be identified — otherwise the replacement pump will suffer the same fate. Speak to one of our engineers about a pump suitability review. Correct sizing, correct installation, and a planned sewage pump servicing schedule are the most effective ways to prevent burnout from recurring.

8. Bad Smells Coming from the Pump

Persistent foul odours usually point to one of three causes: a failed or perished seal on the chamber lid, a cracked vent pipe allowing gases to escape, or stagnant water in a low-usage system where sewage is sitting rather than being regularly moved.

What to do: Have an engineer inspect the pump, chamber lid and vent pipework. In the case of stagnant water, the issue may be resolved by adjusting run times or reviewing the pump sizing. Regular sewage pump maintenance — including checks of seals and vent pipes — will catch this type of deterioration early.

How Planned Sewage Pump Servicing Prevents Most of These Faults

The majority of the faults above share something in common: they don’t appear without warning. Float switches degrade gradually. Seals perish over time. Valves wear. Blockages build up. In almost every case, a planned sewage pump servicing visit would have caught the early signs before they developed into a breakdown.

At Mawdsleys, our sewage pump maintenance visits include:

Visual inspection of the pump, chamber and all pipework
Float switch and level control testing
Non-return valve condition check
Motor insulation and current draw testing
Wet well cleaning and de-ragging
Written condition report with any recommendations

For clients on a servicing contract, we also provide priority response times and discounted call-out rates when emergencies do occur.

If your sewage pump has never been serviced, or your last service visit was more than 12 months ago, it’s worth getting in touch. A single maintenance visit costs a fraction of an emergency repair — and far less than a pump replacement.

Find Out About Our Servicing Contracts →

How Working from Home Could Be Impacting Your Pumps

Advice Booster Pumps Sewage Pumps

One of the biggest impacts on people’s daily routines because of COVID-19 is the increased amount of time they are spending at home, with many continuing to work remotely where they can to adhere to lockdown rules.

Figures from the Office for National Statistics reveal that in April 2020, when the first lockdown was announced, 46.6% of Britain’s workforce did some work at home.

The shift to remote working has posed many challenges, with businesses and staff needing to adapt quickly to ensure staff can work efficiently from home whilst retaining a work/life balance.

A victim of remote working that has perhaps been overlooked is pumps. These systems that we rely on every day keep water pressure high and facilities such as toilets working properly, but with increased usage; these essential systems can run less efficiently and are at a higher risk of failure.

Find out more about the types of pumps that have been impacted by working from home and how building owners can ensure users always get a high level of performance from their pumps in our latest blog post.

The Dangers of Septic Tanks and Cesspits

Advice Dirty Water Pumping Systems Sewage Pumps

If your home or business is out in the countryside or otherwise ‘off the grid’, you may use an alternative sewage treatment method such as a septic tank or cesspit/cesspool.

As well as upcoming changes to legislation making sewage treatment plants the only approved method of waste treatment, septic tanks and cesspools pose a number of risks and can damage the environment around them.

Find out more about the hidden dangers of septic tanks and cesspits and why you should upgrade to a full sewage treatment plant in our latest blog post.

What’s the Difference Between a Septic Tank and a Cesspit?

Contrary to popular belief, a cesspit and a septic tank are two different things – the fundamental difference is that within a cesspit, sewage is simply stored, the cesspit is then emptied by a professional when it is full.

On the other hand, within a septic tank, sewage is stored and partially broken down before being discharged, whilst safer than raw sewage, this discharge is still considered to cause damage to the environment.

The General Binding Rules 2020

The General Binding Rules were first released in 2015 and come into force in 2020. If you have a septic tank that discharges into a body of water such as a stream, you’ll need to upgrade to a sewage treatment plant before 2020.

Additionally, if your current set up is found to be negatively impacting its surrounding environment, or if you are looking to sell your property, you will be required to upgrade sooner.

Dangerous Gases

Due to the nature of what is stored within them, both cesspits and septic tanks contain gases that are potentially harmful to health. Whilst there is no risk when they are sealed in the tank, there are several dangers they hold including:

Rupture of the tank – This can be caused by tree roots and building works and will result in harmful gases being released in the vicinity of the septic tank or cesspit.
Lid collapse – Septic tanks generally have a concrete lid to keep them secure. Over time, the gases can eat away at the lid, causing it to become weaker and increasing the risk of collapse.
Fires – The gases produced by cesspits are extremely flammable, a naked flame should never be anywhere near a cesspit.

Flooding

Flooding of a septic tank can be caused by several circumstances including heavy rain, flooding, blocked pipes, damage to internal components and saturated soil preventing discharge.

If your septic tank is flooding, you will need to reduce or completely restrict the amount of water that is used to avoid contracting an illness and making the problem worse, you find raw sewage backing up into your sinks and toilets.

Additionally, you will need to contact a professional to inspect and service the tank, failure to do so can leave you liable to legal action should the flooding cause a health or pollution risk.

Flooding can cause a lot of damge to your property or the facilities which you manage!

In an emergency call us on 0117 954 8030

Pollution

As cesspits are sealed, they generally only cause damage to the environment around them if they are damaged. However, as septic tanks discharge into bodies of water, they can cause serious damage to the environment, killing wildlife and contaminating private water supplies.

In addition to sewage, a septic tank or cesspit will contain anything that is flushed down the toilet or poured down the sink, this often includes chemical cleaning products, kitchen oils, detergent and human waste.

Inspection Costs

The final danger of cesspits and septic tanks is the amount they will cost you! In addition to installation costs, you will need to pay for regular emptying, inspection and servicing of your cesspit or septic tank in order to prevent it from posing a risk.

Furthermore, if your property currently relies on a septic tank or cesspit, you will have trouble selling it, as the new owners will have to take into consideration all the costs associated with maintaining it and the inevitable cost of upgrading to a sewage treatment plant.

Nationwide Sewage Treatment Plant Installation, Repair and Maintenance

If your property currently handles sewage through a septic tank or cesspit, you will need to upgrade it before 2020. At Mawdsleys Pumps, we provide a nationwide service for the installation, repair and maintenance of sewage treatment plants; we’ll even remove and dispose of the old unit for you.

For more information, give one of our expert team a call today on 0117 954 8030

If your home or business is out in the countryside or otherwise ‘off the grid’, you may use an alternative sewage treatment method such as a septic tank or cesspit/cesspool.

Find out more about the hidden dangers of septic tanks and cesspits and why you should upgrade to a full sewage treatment plant in our latest blog post.

What’s the Difference Between a Septic Tank and a Cesspit?

The General Binding Rules 2020

Additionally, if your current set up is found to be negatively impacting its surrounding environment, or if you are looking to sell your property, you will be required to upgrade sooner.

Dangerous Gases

Rupture of the tank – This can be caused by tree roots and building works and will result in harmful gases being released in the vicinity of the septic tank or cesspit.
Lid collapse – Septic tanks generally have a concrete lid to keep them secure. Over time, the gases can eat away at the lid, causing it to become weaker and increasing the risk of collapse.
Fires – The gases produced by cesspits are extremely flammable, a naked flame should never be anywhere near a cesspit.

Flooding

Flooding of a septic tank can be caused by several circumstances including heavy rain, flooding, blocked pipes, damage to internal components and saturated soil preventing discharge.

Additionally, you will need to contact a professional to inspect and service the tank, failure to do so can leave you liable to legal action should the flooding cause a health or pollution risk.

Flooding can cause a lot of damge to your property or the facilities which you manage!

In an emergency, call us on
0117 954 8030

Pollution

Inspection Costs

Nationwide Sewage Treatment Plant Installation, Repair and Maintenance

For more information, give one of our expert team a call today on 0117 954 8030

Back To School – Are Your Pumps Ready for the New Term?

Advice Booster Pumps Sectors Sewage Pumps

With summer coming to an end, the new term is looming for schools and other educational establishments across the country.

In these environments, proper maintenance of pumps and associated equipment is essential, but stretched budgets, no maintenance plans and lack of knowledge can often result in schools dealing with unexpected breakdowns.

In our latest blog post, we’ll run through the risks of failing to maintain pumping equipment in schools, the pumps most commonly found in schools, checks you can carry out and how Mawdsleys can help ensure your pumps stay up and running all year round.

Winter Sewage Pump Maintenance – Avoid Unexpected Breakdown This Winter

Services Sewage Pumps

A sewage pump failure is never convenient — but it’s almost always preventable. Whether you manage a commercial premises, a residential property or a pumping station, planned sewage pump maintenance is the most reliable way to avoid unexpected breakdowns, protect your equipment and control costs.

This guide explains what good sewage pump maintenance involves, the most common faults that a service visit will catch early, and what to do if your pump develops a problem that needs repair. We also cover why winter is the most critical time to have your system checked — and why Mawdsleys is one of the few pump specialists that keeps operating through the Christmas and New Year period.

Need help now? Call 0117 954 8030 — we operate 24/7, 365 days a year.

What Does Sewage Pump Maintenance Visit Include?

A thorough sewage pump maintenance visit goes well beyond a visual once-over. Our engineers carry out a structured inspection that covers every component likely to cause a failure, including:

Float switch and level controls — the most common cause of pump faults. Tested for correct operation and adjusted or replaced as needed.
Non-return valve condition — a failed valve causes sewage to recirculate within the sump, increasing motor load and wear.
Motor insulation and current draw — an early indicator of winding deterioration before full motor failure occurs.
Pipework and chamber integrity — checking for cracks, perished seals and corrosion that could lead to leaks.
Wet well cleaning and de-ragging — removing rag, debris and silt buildup that impairs pump performance.
Control panel and alarm testing — verifying that high-level alarms and auto-start functions are operating correctly.
Written condition report — a record of findings, any work carried out, and recommendations for the next visit.

Each visit gives you a clear picture of your pump’s condition and flags any developing issues before they become expensive problems.

Common Sewage Pump Problems That Maintenance Prevents

The following faults are among the most frequent reasons we’re called out for emergency sewage pump repair. In most cases, a scheduled maintenance visit would have identified the warning signs first:

Pump not starting. Caused by float faults, a jammed impeller, blocked electrics or motor failure. Our engineers test starting performance on every visit and can spot a weakening motor before it fails completely.

Pump running continuously Usually, a float switch is stuck in the on position, or a blockage prevents the sump level from dropping. Left unattended, the pump runs dry and destroys its seals — turning a simple adjustment into a full sewage pump repair.

Toilets are backing up. Often a downstream blockage or a pump is already working at reduced capacity. Routine maintenance checks flow rates and identifies partial blockages before they cause a full backup.

Leaking pipework or failed non-return valves. Seal and valve degradation is gradual and easy to catch on a maintenance visit. Once a seal fails and sewage begins to leak, it becomes an urgent emergency with potential health and compliance implications.

High-level alarm activating indicates the pump is failing to keep pace with inflow. Maintenance visits test alarm function and verify the pump is handling its design load — preventing the conditions that trigger high-level events.

Bad odours caused by perished chamber lid seals or vent pipe damage. Identified and resolved during a routine service visit before odours became a complaint from building users.

For a deeper look at each of these faults and what causes them, see our guide: 8 Common Problems with Sewage Pumps and How to Fix Them.

Sewage Treatment Plants Undergoing Maintenance

Why Winter Makes Sewage Pump Servicing More Important?

Cold weather puts additional stress on sewage pump systems in several ways:

Freezing temperatures can affect above-ground pipework, vent pipes and any exposed electrical components, particularly on external or partially exposed installations.
Increased usage over the Christmas and New Year period — more people in buildings, hospitality venues running at full capacity — means pumps are working harder precisely when an engineer is hardest to reach.
Holiday shutdowns mean that if a fault develops over Christmas, the impact can go undetected for days, turning a minor fault into significant damage or a sewage overflow.

Arranging a pre-winter sewage pump maintenance visit — ideally in October or November — ensures your system is in the best possible condition before peak demand and cold snaps arrive.

Mawdsleys is one of the few pump specialists that continues operating throughout Christmas and the New Year. Our engineers are available for emergency call-out 24/7, including bank holidays, so if something does go wrong over the festive period, you’re not left waiting.

The Benefits of a Planned Sewage Pump Servicing Contract

For commercial and industrial sites where sewage pumps are business-critical, a servicing contract offers more than just scheduled visits. Our contract clients benefit from:

Priority response times when breakdowns do occur, ahead of non-contract call-outs
Discounted repair rates on parts and labour for any work arising from a service visit
Full service history maintained against each asset — useful for compliance, insurance and handover purposes
Annual condition reporting to support planned budgeting and capital replacement planning
A direct line to a named engineer who knows your site and its equipment

Contracts are tailored to your site and budget — whether you need one visit a year for a single residential pump or quarterly visits across a multi-site estate.

Find out more about our sewage pump servicing contracts →

Why Choose Mawdsleys for Sewage Pump Maintenance and Repair?

30+ years of experience carrying out sewage pump maintenance, repair and servicing across the South West and South Wales
In-house engineers — no subcontracting. Our own team carries out every job, which keeps quality consistent and pricing competitive
Fully equipped workshop in Bristol for pump refurbishment and overhaul when site repair isn’t possible
Confined Space Accredited engineers for work in chambers, wet wells and below-ground installations
24/7 emergency cover, 365 days a year, including Christmas and bank holidays
Trusted by councils and large organisations, including Bristol City Council, North Somerset Council and the Wildfowl & Wetlands Trust

Book a Sewage Pump Maintenance Visit or Service Review

Whether you need a one-off maintenance visit, emergency sewage pump repair, or want to talk through a servicing contract for your site, our team is ready to help.

Call us on 0117 954 8030 or fill in the contact form below. We’ll discuss your requirements and recommend the right approach for your pump and your budget.